It is well known that sexual selection can target reproductive traits during successive pre‐ and post‐mating episodes of selection. A key focus of recent studies has been to understand and quantify ...how these episodes of sexual selection interact to determine overall variance in reproductive success. In this article, we review empirical developments in this field but also highlight the considerable variability in patterns of pre‐ and post‐mating sexual selection, attributable to variation in patterns of resource acquisition and allocation, ecological and social factors, genotype‐by‐environment interaction and possible methodological factors that might obscure such patterns. Our aim is to highlight how (co)variances in pre‐ and post‐mating sexually selected traits can be sensitive to changes in a range of ecological and environmental variables. We argue that failure to capture this variation when quantifying the opportunity for sexual selection may lead to erroneous conclusions about the strength, direction or form of sexual selection operating on pre‐ and post‐mating traits. Overall, we advocate for approaches that combine measures of pre‐ and post‐mating selection across contrasting environmental or ecological gradients to better understand the dynamics of sexual selection in polyandrous species. We also discuss some directions for future research in this area.
Highlights • Circuit regulation of addiction is complex and dynamic. • The pattern and source of dopamine and glutamate neurotransmission in the striatum are critical for shaping addictive processes. ...• Novel techniques are providing new insights into the neural circuits that regulate addiction.
Carbon xerogels were synthesised and used as support of ruthenium-based catalysts for the ammonia decomposition reaction. To improve their physical-chemical properties, carbon xerogels were either ...activated in carbon dioxide atmosphere (for 1 and 5 h), or doped with nitrogen via co-precursor method, using urea as nitrogen source. Un-promoted and sodium-promoted ruthenium catalysts were prepared by incipient wetness impregnation. All catalysts were tested during the ammonia decomposition reaction (1 atm, 100–600 °C), showing high catalytic activity. The 5 h carbon dioxide activation treatment resulted in a decrease in oxygen surface groups (i.e. by 11 wt%) on carbon xerogels surface, and in an increase in the structure crystallinity (i.e. by 15% in the TBurn) of carbon xerogels, resulting in a higher ammonia decomposition reaction rate (i.e. 3.5-fold at 450 °C). Similarly, nitrogen addition to carbon xerogels had a positive effect on the catalysts basicity, enhancing their catalytic performance (i.e. triple reaction rate at 450 °C). The addition of sodium conferred an enhancement in the performance of each catalyst (i.e. reaction rate up to 9 times higher at 450 °C). Two ammonia decomposition reaction runs were performed for all catalysts, to test the performance reproducibility of the catalysts. It was found that un-promoted catalysts exhibited higher reaction rates (i.e. up to 3.5 times at 450 °C) during the second run of reaction due to the larger ruthenium particle size, whereas sodium-promoted catalysts exhibited similar catalytic activity in both reaction runs due to the presence of sodium oxide avoiding the sintering of ruthenium particles.
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•Carbon xerogels are efficient catalyst support for the NH3 decomposition reaction.•CO2 activated and N-doped carbon xerogels show higher crystallinity and basicity.•CO2 activation enhanced the NH3 decomposition rates (up to 3.5 times higher at 450 °C).•The addition of nitrogen lead to a reaction rate 3.2 times higher at 450 °C.•Sodium electronic and structural promoting effects increase the catalytic activity.
When an Au nanoparticle in a liquid medium is illuminated with resonant light of sufficient intensity, a nanometer scale envelope of vapora “nanobubble”surrounding the particle, is formed. This is ...the nanoscale onset of the well-known process of liquid boiling, occurring at a single nanoparticle nucleation site, resulting from the photothermal response of the nanoparticle. Here we examine bubble formation at an individual metallic nanoparticle in detail. Incipient nanobubble formation is observed by monitoring the plasmon resonance shift of an individual, illuminated Au nanoparticle, when its local environment changes from liquid to vapor. The temperature on the nanoparticle surface is monitored during this process, where a dramatic temperature jump is observed as the nanoscale vapor layer thermally decouples the nanoparticle from the surrounding liquid. By increasing the intensity of the incident light or decreasing the interparticle separation, we observe the formation of micrometer-sized bubbles resulting from the coalescence of nanoparticle-“bound” vapor envelopes. These studies provide the first direct and quantitative analysis of the evolution of light-induced steam generation by nanoparticles from the nanoscale to the macroscale, a process that is of fundamental interest for a growing number of applications.
Electricity demand and its typical load pattern are usually affected by many endogenous and exogenous factors to which the generation system must accordingly respond through utility operators. ...Lockdown measures to prevent the spread of COVID-19 imposed by many countries have led to sudden changes in socioeconomic habits which have had direct effects on the electricity systems. Therefore, a detailed analysis of how confinement measures have modified the electricity consumption in Spain, one of the countries most affected by this pandemic, has been performed in this work. Its electricity consumption has decreased by 13.49% from March 14 to April 30, compared to the average value of five previous years. Daily power demand profiles, especially morning and evening peaks, have been modified at homes, hospitals, and in the total power demand. These changes generate a greater uncertainty for the System Operator when making demand forecasts, but production deviations have increased by only 0.1%, thanks to the presence of a diversified generation mix, which has been modified during this period, increasing the proportion of renewable sources and decreasing CO2 emissions.
•Power demand in Spain has decreased by 13.49% due to lockdown measures by COVID-19.•Power demand profiles have changed its usual form on weekdays and weekends.•Average daily deviations in power predictions have only increased by 0.1%.•Renewable power generation has increased during the lockdown.•In March and April 2020, CO2 emissions have decreased by 32.61% compared to 2019.
Field-deployable viral diagnostics using CRISPR-Cas13 Myhrvold, Cameron; Freije, Catherine A; Gootenberg, Jonathan S ...
Science (American Association for the Advancement of Science),
04/2018, Letnik:
360, Številka:
6387
Journal Article
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Mitigating global infectious disease requires diagnostic tools that are sensitive, specific, and rapidly field deployable. In this study, we demonstrate that the Cas13-based SHERLOCK (specific ...high-sensitivity enzymatic reporter unlocking) platform can detect Zika virus (ZIKV) and dengue virus (DENV) in patient samples at concentrations as low as 1 copy per microliter. We developed HUDSON (heating unextracted diagnostic samples to obliterate nucleases), a protocol that pairs with SHERLOCK for viral detection directly from bodily fluids, enabling instrument-free DENV detection directly from patient samples in <2 hours. We further demonstrate that SHERLOCK can distinguish the four DENV serotypes, as well as region-specific strains of ZIKV from the 2015-2016 pandemic. Finally, we report the rapid (<1 week) design and testing of instrument-free assays to detect clinically relevant viral single-nucleotide polymorphisms.
Polaritons in van der Waals materials Basov, D. N.; Fogler, M. M.; de Abajo, F. J. García
Science (American Association for the Advancement of Science),
10/2016, Letnik:
354, Številka:
6309
Journal Article
•Chemical looping is recognised as a promising low cost CO2 capture technology.•The use of biofuels in Chemical looping processes can be an up-and-coming BECCS technology.•Different biofuels and ...chemical looping technologies are considered.•Negative emissions are achieved both during combustion and syngas/H2 production processes.•Bio-Chemical Looping can contribute to reach the target set in the Paris Agreement.
In order to limit the increase in the global average temperature to 2 °C or below, the Paris Agreement proposed the reduction of CO2 emissions throughout this century. Bioenergy with CO2 capture and storage (BECCS) technologies represent an interesting option in order to allow this goal to be metgoal, because they are able to achieve negative CO2 emissions. Chemical looping (CL) is recognized as one of the most innovative CO2 capture technologies owing to its low energy penalty. CL processes permit the utilization of renewable fuels in a nitrogen-free atmosphere, given that the required oxygen is supplied by solid oxygen carriers. The present work presents an overview of the status of development of the use of biofuels in chemical looping technologies, including chemical looping combustion (CLC) and chemical looping with oxygen uncoupling (CLOU) for the production of heat/electricity, as well as chemical looping reforming (CLR), chemical looping gasification (CLG) and chemical looping coupled with water splitting (CLWS) for syngas/H2 generation. The main milestones in the development of such processes are shown, and the future trends and opportunities for CL technology with biofuels are discussed.
In the last decade, solution-processed quantum dot/nanocrystal solar cells have emerged as a very promising technology for third-generation thin-film photovoltaics because of their low cost and high ...energy-harnessing potential. Quantum dot solar cell architectures developed to date have relied on the use of bulk-like thin films of colloidal quantum dots. Here, we introduce the bulk nano-heterojunction concept for inorganic solution-processed semiconductors. This platform can be readily implemented by mixing different semiconductor nanocrystals in solution and allows for the development of optoelectronic nanocomposite materials with tailored optoelectronic properties. We present bulk nano-heterojunction solar cells based on n-type Bi2 S3 nanocrystals and p-type PbS quantum dots, which demonstrate a more than a threefold improvement in device performance compared to their bilayer analogue, as a result of suppressed recombination.
We advocate the widespread use of UV-C light as a short-term, easily deployable, and affordable way to limit virus spread in the current SARS-CoV-2 pandemic. Radical social distancing with the ...associated shutdown of schools, restaurants, sport clubs, workplaces, and traveling has been shown to be effective in reducing virus spread, but its economic and social costs are unsustainable in the medium term. Simple measures like frequent handwashing, facial masks, and other physical barriers are being commonly adopted to prevent virus transmission. However, their efficacy may be limited, particularly in shared indoor spaces, where, in addition to airborne transmission, elements with small surface areas such as elevator buttons, door handles, and handrails are frequently used and can also mediate transmission. We argue that additional measures are necessary to reduce virus transmission when people resume attending schools and jobs that require proximity or some degree of physical contact. Among the available alternatives, UV-C light satisfies the requirements of rapid, widespread, and economically viable deployment. Its implementation is only limited by current production capacities, an increase of which requires swift intervention by industry and authorities.
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