Plasmon-emitter interactions are of central importance in modern nanoplasmonics and are generally maximal at short emitter-surface separations. However, when the separation falls below 10-20 nm, the ...classical theory deteriorates progressively due to its neglect of quantum effects such as nonlocality, electronic spill-out, and Landau damping. Here we show how this neglect can be remedied in a unified theoretical treatment of mesoscopic electrodynamics incorporating Feibelman Formula: see text-parameters. Our approach incorporates nonclassical resonance shifts and surface-enabled Landau damping-a nonlocal damping effect-which have a dramatic impact on the amplitude and spectral distribution of plasmon-emitter interactions. We consider a broad array of plasmon-emitter interactions ranging from dipolar and multipolar spontaneous emission enhancement, to plasmon-assisted energy transfer and enhancement of two-photon transitions. The formalism gives a complete account of both plasmons and plasmon-emitter interactions at the nanoscale, constituting a simple yet rigorous platform to include nonclassical effects in plasmon-enabled nanophotonic phenomena.
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A green approach for the preparation of carbon black (CB) and electrochemically reduced graphene oxide composite (ERGO) is described based on screen printed carbon electrodes (SPCEs) ...fabricated on poly(ethylene terephthalate) (PET) as electrochemical sensors. This approach leads to a heterogeneous hydrophilic surface with high concentration of defect sites according to scanning electron microscopy, contact angle and Raman spectroscopy measurements. The SPCE/CB-ERGO sensor was tested with dopamine (DA), epinephrine (EP) and paracetamol (PCM), exhibiting an enhanced electrocatalytic performance compared to the bare SPCE. It displayed a wider linear range, lower limit of detection and a remarkably higher analytical sensitivity, viz. 1.5, 0.13 and 0.028 A L mol−1 for DA, EP and PCM, respectively, being also capable of simultaneous determination of the three analytes. Such high performance is demonstration that SPCE/CB-ERGO may serve as generic platform for cost-effective flexible electrochemical sensors.
In Southeast Asia, males of the Siamese fighting fish
have been selected across centuries for paired-staged fights. During the selection process, matched for size males fight in a small tank until ...the contest is resolved. Breeders discard losing batches and reproduce winner batches with the aim of increasing fight performance. We assessed the results of this long-term selection process by comparing under standard laboratory conditions male and female aggressive behaviour of one strain selected for staged fights ("fighters") and one strain of wild-types. The aggressive response of adult fish was tested against their mirror image or a size-matched conspecific. Fighter males were more aggressive than wild-type males for all measured behaviours. Differences were not only quantitative but the pattern of fight display was also divergent. Fighter males had an overall higher swimming activity, performing frequent fast strikes in the direction of the intruder and displaying from a distance. Wild-type males were less active and exhibited aggressive displays mostly in close proximity to the stimuli. Females of the fighter strain, which are not used for fights, were also more aggressive than wild-type females. Aggressive behaviours were correlated across male and female fighter siblings, suggesting common genetic and physiological mechanisms to male and female aggression in this species. The study further shows that results were largely independent of the stimulus type, with the mirror test inducing similar and less variable responses than the live conspecific presentation. These results suggest that selection for male winners co-selected for high-frequency and metabolic demanding aggressive display in males and also enhanced female aggression, opening a wide range of testable hypothesis about the ultimate and proximate mechanisms of male and female aggression in
.
•Selection for winners impacted cortisol but not 11-ketotestosterone levels.•Similar androgen response after a mirror fight in wild-type and fighter males.•Cortisol levels increased after a mirror ...fight in wild-type but not fighter males.•Social isolation lowered cortisol in wild-type and androgens in fighter males.•Selection for winning had a stronger impact in the HPI than in the HPG axis.
In southeast Asia, males of the Siamese fighting fish, Betta splendens, have been selected across centuries for winning paired staged fights and previous work has shown that males from fighter strains are more aggressive than wild-types. This strong directional selection for winners is likely to have targeted aggression-related endocrine systems, and a comparison between fighter and wild-type strains can bring into evidence the key hormones implicated in aggression. Here, we compared the plasma levels of the androgen 11-ketotestosterone (KT) and of the corticosteroid cortisol (F) in F2 males of a fighter and a wild-type strain raised under similar laboratory conditions. We show that F was generally lower in fighter as compared with wild-type males, while no overall differences in KT levels were detected between strains. When presented with a mirror-induced aggressive challenge, post-fight levels of F increased but more significantly so in wild-type males, while KT increased in males of both strains. After the challenge, fighter males had higher levels of KT as compared with wild-type males, while the pattern for F was opposite. As compared with animals in social groups, wild-type males placed under social isolation had lower F levels, while KT decreased for fighters.
Taken together, this data suggests that while wild-type males responded to aggression with an increase in circulating levels of both androgens and corticosteroids, males selected for winning fights maintained a blunt F response, increasing only KT levels. These data agree with the hypothesis that a combination of high levels of androgens and low levels of corticosteroids is associated with high aggression. Overall, these results seem to indicate that selection for winning had a stronger impact in the hypothalamus-pituitary-interrenal axis than in the hypothalamus-pituitary–gonadal axis in B. splendens.
Aims
We evaluated the effect of
Azospirillum brasilense
strain HM053 inoculation on maize seeds, a spontaneous mutant that excrete ammonium and fix nitrogen constitutively.
Methods
Maize was grown ...with different nitrogen (urea) concentration and inoculated with
A. brasilense
Ab-V5 (Brazilian commercial strain) or HM053 strain in four field experiments, in three regions of Parana State, Southern Brazil. We evaluated yield components, nutrient content on leaves and grains and productivity during the crop cycle.
Results
Inoculation with
A. brasilense
strain Ab-V5 and HM053 associated with base fertilization (30 kg ha
−1
N) improved crop yield in all trials. Ab-V5 increased production between 2.2 to 10.4%, or 178.0 to 759.9 kg ha
−1
, respectively. HM053, by itself, increased production between 4.7 to 29%, or 460.5 to 1769.3 kg ha
−1
, respectively.
Conclusion
The new strain HM053 showed to be a great biofertilizer for maize seeds and a new alternative for a more sustainable agriculture.
We present a number of statistical tools that show promise for obtaining information on turbulence in molecular clouds (MCs) and diffuse interstellar medium (ISM). For our tests we make use of ...three-dimensional 5123 compressible MHD isothermal simulations performed for different sonic, i.e., , where VL is the injection velocity, Vs is the sound velocity, and Alfvenic , where VA is the Alfven velocity, Mach numbers. We introduce the bispectrum, a new tool for statistical studies of the interstellar medium which, unlike an ordinary power spectrum of turbulence, preserves the phase information of the stochastic field. We show that the bispectra of the three-dimensional stochastic density field and of column densities, available from observations, are similar. This opens good prospects for studies of MCs and diffuse media with the new tool. We use the bispectrum technique to define the role of nonlinear wave-wave interactions in the turbulent energy cascade. We also obtained the bispectrum function for density and column densities with varying magnetic field strength. As expected, a strong correlation is obtained for wave modes k 1 = k 2 for all models. Larger values of result in increased correlations for modes with k 1 k 2. This effect becomes more evident with increasing magnetic field intensity. We believe that the different MHD wave modes, e.g., Alfven and magneto-acoustic, which arise in strongly magnetized turbulence, may be responsible for the increased correlations compared to purely hydrodynamical perturbations. In addition to the bispectrum, we calculated the third and fourth statistical moments of density and column density, namely, skewness and kurtosis, respectively. We found a strong dependence of skewness and kurtosis with . In particular, as increases, so does the Gaussian asymmetry of the density distribution. We also studied the correlations of two-dimensional column density with dispersion of velocities and magnetic field, as well as the correlations of three-dimensional density with magnetic and kinetic energy and for comparison. Our results show that column density is linearly correlated with magnetic field for high . This trend is independent of the turbulent kinetic energy and can be used to characterize inhomogeneities of physical properties in low density clumps in the ISM.
Medicinal use of
L. has an extensive history and it was essential in the discovery of phytocannabinoids, including the
major psychoactive compound-Δ9-tetrahydrocannabinol (Δ9-THC)-as well as the ...G-protein-coupled cannabinoid receptors (CBR), named cannabinoid receptor type-1 (CB1R) and cannabinoid receptor type-2 (CB2R), both part of the now known endocannabinoid system (ECS). Cannabinoids is a vast term that defines several compounds that have been characterized in three categories: (i) endogenous, (ii) synthetic, and (iii) phytocannabinoids, and are able to modulate the CBR and ECS. Particularly, phytocannabinoids are natural terpenoids or phenolic compounds derived from
. However, these terpenoids and phenolic compounds can also be derived from other plants (non-cannabinoids) and still induce cannabinoid-like properties. Cannabimimetic ligands, beyond the
plant, can act as CBR agonists or antagonists, or ECS enzyme inhibitors, besides being able of playing a role in immune-mediated inflammatory and infectious diseases, neuroinflammatory, neurological, and neurodegenerative diseases, as well as in cancer, and autoimmunity by itself. In this review, we summarize and critically highlight past, present, and future progress on the understanding of the role of cannabinoid-like molecules, mainly terpenes, as prospective therapeutics for different pathological conditions.
The COVID-19 pandemic has become one of the main international concerns regarding its impact on mental health. The present study aims to investigate the prevalence of depression, anxiety, and stress ...symptoms, and behavioral aspects amidst the COVID-19 pandemic in a Brazilian population. An online survey was administered from May 22 to June 5, 2020 using a questionnaire comprising of sociodemographic information, the Depression, Anxiety, and Stress Scale (DASS-21), and the Coping Strategies Inventory. Participants comprised 3,000 people from Brazil's 26 states and the Federal District, with an average age of 39.8 years, women (83%), married (50.6%), graduates (70.1%) and employees (46.7%). Some contracted the virus (6.4%) and had dead friends or relatives (22.7%). There was more consumption of drugs, tobacco, medication, and food (40.8%). Almost half of participants expressed symptoms of depression (46.4%), anxiety (39.7%), and stress (42.2%). These were higher in women, people without children, students, patients with chronic diseases, and people who had contact with others diagnosed with COVID-19. The existence of a group more vulnerable to situations with a high stress burden requires greater attention regarding mental health during and after the pandemic. That said, it should be emphasized that these findings are preliminary and portray a moment still being faced by many people amid the pandemic and quarantine measures. Therefore, we understand that the magnitude of the impacts on mental health will only be more specific with continuous studies after total relaxation of the quarantine.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Tuning electrical, optical, and thermal material properties is central for engineering and understanding solid-state systems. In this scenario, atomically thin materials are appealing ...because of their sensitivity to electric and magnetic gating, as well as to interlayer hybridization. Here, we introduce a radically different approach to material engineering relying on the image interaction experienced by electrons in a two-dimensional material when placed in proximity of an electrically neutral structure. We theoretically show that electrons in a semiconductor atomic layer acquire a quantum phase resulting from the image potential induced by the presence of a neighboring periodic array of conducting ribbons, which in turn modifies the optical, electrical, and thermal properties of the monolayer, giving rise to additional interband optical absorption, plasmon hybridization, and metal-insulator transitions. Beyond its fundamental interest, material engineering based on the image interaction represents a disruptive approach to tailor the properties of atomic layers for application in nanodevices.
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