Nowadays, due to the increasing use of electric vehicles, manufacturers are making more and more innovations in the batteries used in electromobility, in order to make these vehicles more efficient ...and provide them with greater autonomy. This has led to the need to evaluate and compare the efficiency of different batteries used in electric vehicles to determine which one is the best to be implemented. This paper characterises, models and compares three batteries used in electromobility: lithium-ion, lead-acid, and nickel metal hydride, and determines which of these three is the most efficient based on their state of charge. The main drawback to determine the state of charge is that there are a great variety of methods and models used for this purpose; in this article, the Thévenin model and the Coulomb Count method are used to determine the state of charge of the battery. When obtaining the electrical parameters, the simulation of the same is carried out, which indicates that the most efficient battery is the Lithium-ion battery presenting the best performance of state of charge, reaching 99.05% in the charging scenario, while, in the discharge scenario, it reaches a minimum value of 40.68%; in contrast, the least efficient battery is the lead acid battery, presenting in the charging scenario a maximum value of 98.42%, and in the discharge scenario a minimum value of 10.35%, presenting a deep discharge. This indicates that the lithium-ion battery is the most efficient in both the charge and discharge scenarios, and is the best option for use in electric vehicles. In this paper, it was decided to use the Coulomb ampere counting method together with the Thévenin equivalent circuit model because it was determined that the combination of these two methods to estimate the SOC can be applied to any battery, not only applicable to electric vehicle batteries, but to battery banks, BESS systems, or any system or equipment that has batteries for its operation, while the models based on Kalman, or models based on fuzzy mathematics and neural networks, as they are often used and are applicable only to a specific battery system.
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El comportamiento del consumidor pasa por cinco etapas: reconocimiento del problema, búsqueda de información, evaluación de alternativas, decisión de compra y comportamiento poscompra. El objetivo es ...determinar los criterios de decisión que se presentan en cada una de las etapas del proceso de compra del consumidor y la relación que existe entre sí de forma sistematizada entre los consumidores que compran alimentos de restaurantes y cafeterías. Se realizó un estudio cuantitativo, no experimental, de nivel descriptivo y transversal en 385 consumidores. Como resultado, se identificaron 41 aspectos que el consumidor evalúa ante una decisión de compra, distribuidos en cada una de las etapas del proceso. Se concluye que existe una relación entre los factores que conforman cada una de las dimensiones.
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Climatic dryness imposes limitations on vascular plant growth by reducing stomatal conductance, thereby decreasing CO2 uptake and transpiration. Given that transpiration‐driven water flow is required ...for nutrient uptake, climatic stress‐induced nutrient deficit could be a key mechanism for decreased plant performance under prolonged drought. We propose the existence of an “isohydric trap,” a dryness‐induced detrimental feedback leading to nutrient deficit and stoichiometry imbalance in strict isohydric species. We tested this framework in a common garden experiment with 840 individuals of four ecologically contrasting European pines (Pinus halepensis, P. nigra, P. sylvestris, and P. uncinata) at a site with high temperature and low soil water availability. We measured growth, survival, photochemical efficiency, stem water potentials, leaf isotopic composition (δ13C, δ18O), and nutrient concentrations (C, N, P, K, Zn, Cu). After 2 years, the Mediterranean species Pinus halepensis showed lower δ18O and higher δ13C values than the other species, indicating higher time‐integrated transpiration and water‐use efficiency (WUE), along with lower predawn and midday water potentials, higher photochemical efficiency, higher leaf P, and K concentrations, more balanced N:P and N:K ratios, and much greater dry‐biomass (up to 63‐fold) and survival (100%). Conversely, the more mesic mountain pine species showed higher leaf δ18O and lower δ13C, indicating lower transpiration and WUE, higher water potentials, severe P and K deficiencies and N:P and N:K imbalances, and poorer photochemical efficiency, growth, and survival. These results support our hypothesis that vascular plant species with tight stomatal regulation of transpiration can become trapped in a feedback cycle of nutrient deficit and imbalance that exacerbates the detrimental impacts of climatic dryness on performance. This overlooked feedback mechanism may hamper the ability of isohydric species to respond to ongoing global change, by aggravating the interactive impacts of stoichiometric imbalance and water stress caused by anthropogenic N deposition and hotter droughts, respectively.
We propose a new conceptual model (termed “isohydric trap”) that links nutrient uptake to stomatal regulation under climatic dryness. This model predicts that plant species with tight stomatal control will experience large reductions in uptake of nutrients with low mobility in soil such as P and K, leading to severe nutrient deficit and imbalance under prolonged drought stress. To test this model, we conducted a common garden experiment with four pine species differing in drought tolerance. We demonstrate that a large decrease in transpiration‐driven nutrient harvesting is a key underlying mechanism contributing to explain poor plant performance and forest dieback under a hotter‐drought scenario.
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Increases in species diversity and density from higher to lower latitudes are well documented. Nevertheless, the consequences of these changes in diversity for structuring ecological communities and ...influencing biotic evolution are largely unknown. It is widely believed that this increase in species diversity is associated with increased intensity of ecological interactions closer to the equator. For plant–herbivore interactions in particular, the predictions are that, at lower latitudes, plants will be attacked by more individual herbivores, more herbivore species, and more specialized herbivores and, therefore, will suffer greater damage. We used a large-scale latitudinal transect from Mexico to Bolivia to quantify changes in leaf damage, diversity, and abundance of lepidopteran larvae on two widely distributed host species of the genus Piper (Piperaceae). We show that both density and species richness of herbivores were highest at the equator and decreased with increasing latitude, both northward and southward. Contrary to expectation, however, this increase in herbivore diversity was attributable to the addition of generalist not specialist species. Finally, and again contrary to expectation, the increase in herbivore density with decreasing latitude did not produce a corresponding damage gradient. We propose that the lack of a latitudinal concordance between increases in herbivore density and diversity with decreasing latitude, and the resulting herbivore damage, supports the hypothesis of better plant antiherbivore defenses at lower latitudes. Furthermore, the changes in the relative abundance of generalist vs. specialist species suggest that the nature of the selective pressure is intrinsically different between higher and lower latitudes.
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Aim
Climate change is altering habitat suitability for many organisms and modifying species ranges at a global scale. Here we explored the impact of climate change on 112 pine species (Pinus), ...fundamental elements of Northern terrestrial ecosystems.
Location
Global.
Methods
We applied a novel methodology for species distribution modelling that considers uncertainty in climatic projections and taxon sampling, and incorporates elements of species' recent evolutionary history. We based our niche calculations on climate and soil data and computed projections across multiple algorithms and IPCC scenarios, which were ensembled into one single suitability map. We then used phylogenetic methods to account for recent evolution in climatic requirements by estimating the evolution of climatic niche. Edaphoclimatic and evolutionary analyses were then combined to calibrate the projections in areas showing high uncertainty. We validated our models using naturalized occurrences of invasive pine species.
Results
Our models predicted that by 2070, most pine species (58%) might face important reductions of habitat suitability, potentially leading to range losses and a decrease in species richness, particularly in some regions such as the Mediterranean Basin and South North America, albeit migration might mitigate these shifts in some cases. In contrast, our projections showed increased habitat suitability for approx. 20% of species, which may undergo range expansions under climate change. Moreover, the consideration of recent evolutionary trends modified projected scenarios, decreasing range loss and increasing range expansion for some species. The independent validation endorsed our models for many species and the influence of recent evolution in some cases.
Conclusions
We predict that climate change will impose drastic changes in pine distribution and diversity across biogeographical regions, but the magnitude and direction of change will vary significantly across regions and taxa. Species‐level responses are likely to be influenced by regional conditions and the recent evolutionary history of each taxon.
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6.
Rethinking the Inka Hayashida, Frances M; Troncoso, Andrés; Salazar, Diego
02/2022
eBook
2023 Book Award, Society for American Archaeology A
dramatic reappraisal of the Inka Empire through the lens of
Qullasuyu. The Inka conquered an immense area extending
across five modern nations, yet ...most English-language publications
on the Inka focus on governance in the area of modern Peru. This
volume expands the range of scholarship available in English by
collecting new and notable research on Qullasuyu, the largest of
the four quarters of the empire, which extended south from Cuzco
into contemporary Bolivia, Argentina, and Chile.
From the study of Qullasuyu arise fresh theoretical perspectives
that both complement and challenge what we think we know about the
Inka. While existing scholarship emphasizes the political and
economic rationales underlying state action, Rethinking the
Inka turns to the conquered themselves and reassesses imperial
motivations. The book's chapters, incorporating more than two
hundred photographs, explore relations between powerful local lords
and their Inka rulers; the roles of nonhumans in the social and
political life of the empire; local landscapes remade under Inka
rule; and the appropriation and reinterpretation by locals of Inka
objects, infrastructure, practices, and symbols. Written by some of
South America's leading archaeologists, Rethinking the
Inka is poised to be a landmark book in the field.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has changed our lives. The scientific community has been investigating re-purposed treatments to prevent disease progression in coronavirus ...disease (COVID-19) patients.
To determine whether ivermectin treatment can prevent hospitalization in individuals with early COVID-19.
A randomized, double-blind, placebo-controlled study was conducted in non-hospitalized individuals with COVID-19 in Corrientes, Argentina. Patients with SARS-CoV-2 positive nasal swabs were contacted within 48 h by telephone to invite them to participate. The trial randomized 501 patients between August 19th 2020 and February 22nd 2021.
Patients were randomized to ivermectin (N = 250) or placebo (N = 251) arms in a staggered dose, according to the patient's weight, for 2 days.
The efficacy of ivermectin to prevent hospitalizations was evaluated as primary outcome. We evaluated secondary outcomes in relationship to safety and other efficacy end points.
The mean age was 42 years (SD ± 15.5) and the median time since symptom onset to the inclusion was 4 days interquartile range 3-6. The primary outcome of hospitalization was met in 14/250 (5.6%) individuals in ivermectin group and 21/251 (8.4%) in placebo group (odds ratio 0.65; 95% confidence interval, 0.32-1.31; p = 0.227). Time to hospitalization was not statistically different between groups. The mean time from study enrollment to invasive mechanical ventilatory support (MVS) was 5.25 days (SD ± 1.71) in ivermectin group and 10 days (SD ± 2) in placebo group, (p = 0.019). There were no statistically significant differences in the other secondary outcomes including polymerase chain reaction test negativity and safety outcomes.
Low percentage of hospitalization events, dose of ivermectin and not including only high-risk population.
Ivermectin had no significant effect on preventing hospitalization of patients with COVID-19. Patients who received ivermectin required invasive MVS earlier in their treatment. No significant differences were observed in any of the other secondary outcomes.
ClinicalTrials.gov NCT04529525 .
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This article, building on the emerging theoretical corpus of “reputation theory” provides an alternative explanation about how successful policies are obtained in contexts of bureaucratic weakness ...and volatile politics. The argument is that politicians choose to intervene in delivering successful policies based on how contributable such policies are to construct their political reputations. The findings suggest that in both countries, less tenured politicians face higher incentives to build their reputations, so they choose to deliver better policies to accumulate “successful experiences” as vitae for electoral purposes. Tenured politicians, in turn, opt for inaction or strategic delivery, to preserve their already won political reputations. The present article brings evidence from the education sector of Peru and Bolivia, a sector that has been at the core of these countries' priorities for decades. Through a mixed methods approach involving a panel regression and in‐depth interviews, results obtained largely confirm this article's claims.
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Floral scent is crucial for attracting pollinators, especially in plants that bloom at night. However, chemical profiles of flowers from nocturnal plants with varied floral morphs are poorly ...documented, limiting our understanding of their pollination ecology. We investigated the floral scent in Guettarda scabra (L.) Vent. (Rubiaceae), a night-blooming species with short- and long-styled floral morphs, found in the threatened pine rocklands in south Florida, US. By using dynamic headspace sampling and GC–MS analysis, we characterized the chemical profiles of the floral scent in both morphs. Neutral red staining was also employed to determine the specific floral regions responsible for scent emission in G. scabra. The results revealed that G. scabra’s fragrance consists entirely of benzenoid and terpenoid compounds, with benzeneacetaldehyde and (E)-β-ocimene as dominant components. There were no differences in the chemical profiles between the long- and short-styled flowers. Staining assays indicated that the corolla lobes, anthers, and stigma were the primary sources of the scent. These findings indicate that G. scabra’s floral scent is consistent with that of night-blooming plants pollinated by nocturnal hawkmoths, providing important insights into its chemical ecology and pollinator attraction. This study demonstrates how floral scent chemistry can validate predictions based on flower morphology in hawkmoth-pollinated plants.
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