21 research outputs found
Positive adjacency effects mediated by seed disperser birds in pine plantations
This study examines the consequences of adjacent elements for a given patch, through their effects on zoochorous dispersion by frugivorous birds. The case study consists of pine plantations (the focal patch) adjacent to other patches of native vegetation (mixed patches of native forest and shrublands), and/or pine plantations. Our hypothesis is that input of native woody species propagules generated by frugivorous birds within plantations strongly depends on the nature of the surrounding vegetation. To test this hypothesis, we studied frugivorous-bird abundance, seed dispersion, and seedling establishment in nine pine plantation plots in contact with patches of native vegetation. To quantify adjacency arrangement effects, we used the percentage of common border between a patch and each of its adjacent elements. Frugivorous bird occurrence in pine plantations is influenced by the adjacent vegetation: the greater the contact with native vegetation patches, the more abundant were the frugivorous birds within pine plantations. Furthermore, frugivorous birds introduce into plantations the seeds of a large sample of native fleshy-fruited species. The results confirm the hypothesis that zoochorous seed rain is strongly determined by the kind of vegetation surrounding a given plantation. This finding underlines the importance of the composition of the mosaic surrounding plantations and the availability of mobile link species as key landscape features conditioning passive restoration processes
Sensitivity improvement of a humidity sensor based on silica nanospheres on a long-period fiber grating
This work addresses a new configuration that improves the sensitivity of a humidity sensor based on a long-period fiber grating coated with a SiO(2)-nanospheres film. An intermediate higher refractive index overlay, deposited through Electrostatic Self-Assembly, is placed between the fiber cladding and the humidity sensitive film in order to increase the total effective refractive index of the coating. With this intermediate design, a three-fold improvement in the sensitivity was obtained. Wavelength shifts up to 15 nm against 5 nm were achieved in a humidity range from 20% to 80%.This work was supported in part by Fundação para a Ciência e Tecnologia (FCT) with the grant
SFRH/BD/30086/200
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Relación entre la variabilidad espacial de la conductividad eléctrica y el contenido de sodio del suelo Relationship between spatial variability of electrical conductivity and soil sodium content
La agricultura de precisión utiliza herramientas modernas capaces de facilitar la obtención y análisis de datos georreferenciados. La conductividad eléctrica aparente (CEa) del suelo, se obtiene con sensores remotos y está correlacionada con algunas propiedades del suelo (capacidad de almacenamiento de agua, contenido de materia orgánica, salinidad y drenaje, topografía, manejos previos y texturas entre otras). El exceso de sales puede ser perjudicial para las plantas mientras que altos contenidos de sodio intercambiable pueden provocar daños físicos y químicos en el suelo, afectando el crecimiento de los cultivos. Se seleccionaron 3 lotes con una superficie promedio de 80 ha, regados con pivote central, en el sudeste de la provincia de Buenos Aires, Argentina. En cada lote se midió la CEa georreferenciada con un sensor de medición directa. Con los datos obtenidos se confeccionaron mapas de CEa utilizando técnicas de interpolación espacial (Kriging). Los campos fueron divididos en zonas de igual rango de CEa, para tomar muestras de suelo en las que se midió humedad gravimétrica (θg), CE del extracto de saturación (CEe) y cationes solubles (Na+, Ca+2 y Mg+2). Se calculó la relación de adsorción de sodio (RAS). Los datos fueron analizados estadísticamente utilizando el procedimiento PROC MIXED de SAS. Se observó variabilidad espacial de la CEa y se detectó una asociación entre la CEa y el RAS. Existe una relación significativa entre la CEa, la CEe y el contenido de sodio del suelo, diferenciándose estadísticamente los contenidos de Na+ entre las diferentes zonas de CEa de cada lote. Los sensores de medición directa de CEa son herramientas eficaces para la estimación espacial del contenido de sodio del suelo.<br>Precision agriculture utilizes modern tools in order to obtain and analyze georreferenced data. Direct measuring sensors of soil apparent electrical conductivity (ECa) are part of these modern tools and are widely used to quantify ECa spatial variability. This variable is correlated with other soil properties (water holding capacity, organic matter content, salinity, drainage, topography, tillage managing and soil texture). Plants are negatively affected by elevated salts amount and elevated exchangeable sodium content, which causes physical and chemical damage of soils, affecting crop's grown and production. In order to determinate sodium spatial content and distribution, three fields about 80 Has average were selected. All fields are under central pivot irrigation system and are located in the southeast of Buenos Aires province, Argentina. In these fields ECa was measured and georreferenced whit a direct measure sensor. Obtained data was used to create ECa maps in every field using spatial interpolation methods (Kriging). All fields were divided into four different zones, based on its ECa value, where soil samples were taken. Soil samples were laboratory processed in order to determinate gravimetric humidity (θg),, electrical conductivity of soil saturation paste extract (ECe) and soluble cations (Na+, Ca+2 and Mg+2), and sodium adsorption ratio (SAR) was calculated. Experimental data was statistically analyzed using SAS PROC MIXED procedure. We observed CEa spatial variability, and associations between ECa and SAR. Significantly relationships between ECa, ECe and soil sodium content were found. Sodium content was statistically differenced between different ECa zones in every field. The ECa direct measuring sensors are accurately tools to estimate soil sodium spatial content
The Oceanic Anoxic Event 2 organic record in the South Iberian Paleomargin.
International audienceThe Cenomanian—Turonian boundary is marked by one of the warmest periods of the Mesozoic, associated with high pCO2 levels and global sea-level highstands. Coupled to these extreme conditions is a massive magmatic episode, the establishment of worldwide marine anoxia, the deposition of organic-rich facies, and perturbations of the global carbon cycle, the so-called Oceanic Anoxic Event 2 (OAE2). In order to define the organic facies variability, this stratigraphic interval was analysed in the Baños de la Hedionda, a reference section positioned in the W part of the Internal Subbetic, representing the sedimentary record of a pelagic plateau located in the most distal part of the South Iberian Paleomargin. Regarding this goal, a high resolution study was developed on the Capas Blancas Formation (Capas Blancas, Black radiolaritic shales, and Boquerón members - Mb.), using organic petrographic and geochemical techniques. Carbon isotopic profile, for the isolated kerogen (δ13Ckerogen), displays a positive excursion of ~2.5‰ observed in the Black radiolaritic shales Mb., which is in accordance with the worldwide recognized trend for the OAE2 isotopic record.The pre-OAE2 is represented by the Capas Blancas Mb., with the majority of the samples of this unit showing no organic matter (OM) recovery (0.01—0.57 wt.% total organic carbon; TOC). Palynofacies analysis displayed an association co-dominated by the Amorphous and Palynomorph groups. The Amorphous Group is characterized mostly by marine phytoplankton-derived amorphous OM (AOM), while the Palynomorph Group is co-dominated by freshwater microplankton (Zygnemataceae and Closterium) and choanoflagellates, with some specimens of marine microplankton, sporomorphs, and zoomorphs being also identified. The mixture of freshwater and marine components suggest deposition in a platform environment with shallow depths and oscillating oxygen regimen (oxic to dysoxic conditions). The freshwater components are most likely transported into the marine system due to the lower amorphization state, with the source area being in high proximity.The OAE2, represented by the Black radiolaritic shales Mb., is characterized by a dominance of: (i) marine phytoplankton-derived AOM; (ii) plate-like bacterial AOM; and, (iii) sheet-like bacterial AOM with a cratered aspect (0.36—31.48 wt.% TOC). Choanoflagelates (with high degree of amorphization) at the base of the unit, zooclasts, sporomorphs, and solid bitumen are also present. The change in the organic facies suggests the occurrence of a transgressive phase. This organic facies is indicative of a relative sea level rise, with O2 conditions deteriorating with the emplacement of reducing conditions, possibly related to an increase in primary productivity.The post-OAE2, recognized in the Boquerón Mb., is characterized by a co-dominance of marine phytoplankton-derived AOM and palynomorphs, namely zoomorphs, and high percentages of opaque phytoclasts (below 0.25 wt.% TOC). Nevertheless, kerogen displays a reworked character and, therefore, data should be used with caution.Furthermore, this study constitutes the first record of Closterium in sediments from the Cretaceous, and the first identification of choanoflagellates, the closest living relatives of Metazoa, in the fossil record
Diet–demography relationships in a long-lived predator: from territories to populations
Understanding the mechanisms that shape animal population dynamics is of fundamental interest in ecology, evolution and conservation biology. Food supply is an important limiting factor in most animal populations and may have demographic consequences. Optimal foraging theory predicts greater consumption of preferred prey and less diet diversity when food is abundant, which may benefit key fitness parameters such as productivity and survival. Nevertheless, the correspondence between individual resource use and demographic processes in populations of avian predators inhabiting large geographic areas remains largely unexplored, particularly in complex ecosystems such as those of the Mediterranean basin. Based on a long-term monitoring program of the diet and demography of Bonelli’s eagle Aquila fasciata in western Europe, here we test the hypothesis that a predator’s diet is correlated to its breeding productivity and survival at both the territorial and population levels, and ultimately to its population growth rate. At the territorial level, we found that productivity increased with greater consumption of European rabbits Oryctolagus cuniculus, the Bonelli’s eagle’s preferred prey, and pigeons, an important alternative prey for this predator. The survival of territorial pairs was negatively affected by higher diet diversity, which probably reflected the inability to find sufficient high quality prey. Diet effects at the population level were similar
but more noticeable than at the territorial level, i.e. a greater consumption of rabbits, together with lesser consumption of small-to-medium avian species (‘other birds’; non-preferred prey), increased productivity, while greater diet diversity and lower consumption of rabbits was associated with reduced survival and population growth rate. Overall, our study illustrates how the diet of a predator species can be closely related to key individual vital rates, which, in turn, leave a measurable fingerprint on population dynamics within and among populations across large spatial scales
Variations in the phytoremediation efficiency of metal-polluted water with Salvinia biloba : prospects and toxicological impacts
Abstract: The occurrence of heavy metals in industrial wastewater is unanimously considered a major
concern since these pollutants cannot be chemically or biologically degraded and therefore have
long residence times. Phytoremediation is one of the most widespread biotechnological applications
worldwide, which consists in the use of plants to adsorb or accumulate a broad range of inorganic and
organic contaminants from water, air, and soil. To improve the cost-effectiveness and sustainability of
phytoremediation-based wastewater treatment systems, it is essential to use plants that are not only
efficient in pollutants removal, but also abundant and easily accessible at the target site, requiring
no-special culture conditions. In this study, we have evaluated the capacity of naturally-occurring
aquatic macrophytes of the genus Salvinia (classified as Salvinia biloba) to phytoremediate water
artificially contaminated with cadmium (Cd), copper (Cu), lead (Pb), or zinc (Zn) at equal molar
concentrations (50 ± 2 and 100 ± 1 µM), during 48 h. Additionally, photosynthetic and antioxidant
pigments (carotenoids, chlorophylls, anthocyanins, and flavonoids), and soluble carbohydrate content
was also measured in floating leaves of Salvinia specimens to appraise heavy metals phytotoxicity.
Elemental analyses to plant tissue indicate that S. biloba was able to bioconcentrate all four metals
analyzed, albeit with different degrees of affinity. In addition, the mechanisms of uptake and
detoxification were dissimilar for each ion, resulting in greater removal of Cu and Pb (≥96%, at both
concentrations), in comparison to Cd (79 ± 4% and 56 ± 2% for 50 ± 2 and 100 ± 1 µM, respectively)
and Zn (77 ± 5% and 70 ± 4% for 50 ± 2 and 100 ± 1 µM, respectively). Accordingly, the assessment of
the selected physiological parameters in floating leaves suggests that different response mechanisms
are triggered by each metal in S. biloba to counteract the corresponding toxicological stress
Potential of salvinia biloba raddi for removing atrazine and carbendazim from aquatic environments
Abstract:
In this exploratory study, naturally occurring Salvinia biloba Raddi specimens were assessed for atrazine and carbendazim
polluted water remediation. Experiments were carried out over 21 days in glass vessels containing deionized water artifcially
contaminated with 0, 5, 10, and 20 mg L−1 of atrazine or carbendazim. Atrazine had a pronounced detrimental impact on
S. biloba, as no biomass development was observed in all macrophytes exposed to this herbicide in the entire concentration
range. However, carbendazim-treated plants were able to grow and survive in the polluted medium even when subjected to
the highest concentration of this fungicide (i.e., 20 mg L−1). In addition, increased chlorosis and necrosis were also detected
in plants subjected to carbendazim as a result of the high phytotoxicity caused by atrazine. A maximal removal efciency
of~30% was observed for both pesticides at 5 mg L−1 and decreased with increasing concentrations of the pollutants. The
spectrum of the FTIR-ATR analysis revealed the existence of various functional groups (e.g., amide, carboxyl, hydroxyl,
phosphate, sulfate) on the plants, which could be related to pesticide biosorption. In addition, at the end of the 21-day
assay, seven carbendazim-resistant bacteria could be isolated from the roots of fungicide-treated plants. Therefore, the use
of autochthonous free-foating S. biloba macrophytes for phytoremediation of aquatic environments contaminated with
carbendazim shows great promise. Still, additional research is required to further elucidate the plant-mediated carbendazim
elimination process and the role of the herbicide-resistant bacteria, and seek alternative species capable of mitigating atrazine
contamination