Core excitation in Ozone localized to one of two symmetry-equivalent chemical bonds - molecular alignment through vibronic coupling

Core excitation from terminal oxygen O$_T$ in O$_3$ is shown to be an excitation from a localized core orbital to a localized valence orbital. The valence orbital is localized to one of the two equivalent chemical bonds. We experimentally demonstrate this with the Auger Doppler effect which is observable when O$_3$ is core-excited to the highly dissociative O$_{T}$1s$^{-1}$7a$_1^1$ state. Auger electrons emitted from the atomic oxygen fragment carry information about the molecular orientation relative to the electromagnetic field vector at the moment of excitation. The data together with analytical functions for the electron-peak profiles give clear evidence that the preferred molecular orientation for excitation only depends on the orientation of one bond, not on the total molecular orientation. The localization of the valence orbital "7a$_1$" is caused by mixing of the valence orbital "5b$_2$" through vibronic coupling of anti-symmetric stretching mode with b$_2$-symmetry. To the best of our knowledge, it is the first discussion of the localization of a core excitation of O$_3$. This result explains the success of the widely used assumption of localized core excitation in adsorbates and large molecules

Recognition of the ligand-type specificity of classical and non-classical MHC I proteins.

Functional characterization of proteins belonging to the MHC I superfamily involves knowing their cognate ligands, which can be peptides, lipids or none. However, the experimental identification of these ligands is not an easy task and generally requires some a priori knowledge of their chemical nature (ligand-type specificity). Here, we trained k-nearest neighbor and support vector machine classifiers that predict the ligand-type specificity MHC I proteins with great accuracy. Moreover, we applied these classifiers to human and mouse MHC I proteins of uncharacterized ligands, obtaining some results that can be instrumental to unravel the function of these proteins

Vibrational corrections to hyperpolarizabilities of the O3, SO2, N2O and CO2 molecules: A comparison between variational and perturbation methods

AbstractIn this work we reported results of vibrational corrections to the first and second hyperpolarizabilities of the O3, SO2, N2O and CO2 molecules at the CCSD level through the BKPT method of Bishop and Kirtman and also using a variational approximation proposed in a previous work. Comparison between results obtained by both methods shows that the performance of BKPT is different for the systems studied here. Practically the same results are obtained for sulfur dioxide while ozone is the system for which there is greater discrepancy between the results obtained by the two procedures

A monograph of the genus Pheidole in Florida (Hymenoptera: Formicidae)

The genus Pheidole is one of the more important ant genera in the world Approximately 1000 species are now known. Over 400 of these are found in the Neotropical region (Kempf, 1972), and about 75 taxa are known from North America north of Mexico. Pheidole spp. are abundant in many areas, and live in varying habitats ranging from the humid tropics to deserts. They are able to survive in some areas by their habits of collecting and storing seeds as food resources. They are also scavengers of dead insects and other animals, and can be predacious. Some species tends aphids and other homopterans, but this food source, so important to many ant species, is probably of relatively minor importance to most species of Pheidole

The ins and outs of nanoparticle technology in neurodegenerative diseases and cancer.

As we enter the twenty-first century, several therapies based on using nanoparticles (NPs) ranging in size 1 - 1000 nm have been successfully brought to the clinic to treat cancer, pain and infectious diseases. These therapies bring together the ability of NPs to target the delivery of drugs more precisely, to improve solubility, to prevent degradation, to improve their therapeutic index and to reduce the immune response. NPs come in all shapes and sizes, designed specifically for biomedical applications such as solid lipid polymers, liposomes, dendrimers, nanogels, and quantum dots. These NPs offer many attractive characteristics such as biological stability and biocompatibility, thus incorporating different biological or drug molecules. Among the major therapeutic challenges from neurological diseases through to cancer is the development of nanomaterials that are able to be effective against the disease. In the case of neurodegeneration, one of the most difficult areas to penetrate for drug discovery in the body is the central nervous system, protected by the blood-brain-barrier. Whilst in the case of cancer, the biggest problem is how to specifically target a tumor with sufficient drug without causing side effects or inducing resistance. A new generation of intelligent NPs are emerging for the treatment of human disease such as neurological disorders and cancer. The use of natural alternative therapy is an encouraging idea in drug discovery. To this end as we gain more knowledge into the biological function of exosomes, this will allow us to harness their potential as natural NPs in future therapeutics

Redução da viabilidade de esporângios de Plasmopara viticola por bactérias nativas do filoplano da videira.

Resumo: O míldio é uma das principais doenças da videira, capaz de causar danos significativos à cultura e aumentar os custos de produção. Seu controle demanda o uso intensivo de agrotóxicos, cujos resíduos são indesejáveis. Este trabalho teve como objetivo investigar o potencial uso de bactérias do filoplano em reduzir a viabilidade de esporângios de Plasmopara viticola. Foram testados trinta e cinco isolados bacterianos obtidos do filoplano de videira. Os testes de antagonismo foram feitos em lâminas de microscopia e em discos de folha, adicionando-se 50 microL de uma suspensão bacteriana e 50 microL de uma suspensão de esporângios. Nos testes em lâmina de microscopia, vinte e nove isolados inibiram a germinação dos esporângios de Plasmopara viticola. Destes, os isolados 1, 37 e 12 se destacaram, por serem capazes de inibir também a liberação de zoósporos. Em discos de folha, o isolado 1 foi o único capaz de inibir a liberação dos zoósporos, significativamente em relação à testemunha. Nesta condição, não houve a germinação dos esporângios, apenas a liberação de zoósporos. Abstract: The downy mildew is one of the main grapevine diseases, able to cause significant damage to the crop and increase production costs. It?s control demand intensive use of pesticides, which residues are undesirable. This study aimed to investigate the potential of phylloplane bacteria in reducing the viability of sporangia of Plasmopara viticola. Thirty-five bacterial isolates from phylloplane of grapevine were tested. The antagonism tests were conducted on microscopy glass blades and on leaf discs, adding microL of a bacterial suspension and 50 microL of a suspension of sporangia. Twenty-nine isolates inhibited the germination of the sporangia of Plasmopara viticola in tests conducted on glass blades. Of these, isolates 1, 37 and 12 were able to inhibit the release of zoospores. In the leaf discs test, the isolate 1 was the single able to inhibit the release of zoospores, significant compared to the control. In this condition, there wasn?t germination of sporangia, only zoospores release

Behavioral interactions are modulated by facilitation along a heterotrophic succession

Competition and facilitation drive ecological succession but are often hard to quantify. In this sense, behavioral data may be a key tool to analyze interaction networks, providing insights into temporal trends in facilitation and competition processes within animal heterotrophic succession. Here, we perform the first in-depth analysis of the factors driving temporal dynamics of carcass consumption by analyzing behavioral patterns (i.e., interactions) and community dynamics metrics (i.e., species richness, abundance, turnover, and diversity) in a Neotropical scavenger guild. For this purpose, we monitored goat carcasses using automatic cameras. From 573 reviewed videos, we registered 1784 intraspecific and 624 interspecific interactions, using intraspecific and interspecific aggressions (n = 2048) as a behavioral proxy of competition intensity. Our results show that resource availability shapes behavioral interactions between vultures, with a specific effect of the different species on behavioral and competition dynamics, showing the existence of a hierarchy between species. Furthermore, behavioral processes linked to carcass opening tended to be facilitative, related to moments of higher tolerance (i.e., lower aggressiveness), thus reducing competition intensity and also affecting community structure and dynamics. This novel framework demonstrates complex ephemeral successional processes characterized by a fluctuation in facilitation and competition intensity during the consumption of an unpredictable resource linked to key ecosystem processes.Lara Naves-Alegre, and Esther Sebastián-González were supported by the Generalitat Valenciana and the European Social Fund (ACIF/2019/056, SEJI/2018/024, respectively). Esther Sebastián-González also received the grant RYC2019-027216-I funded by MCIN/AEI/ 10.13039/501100011033 and by ESF Investing in Your Future

Contrasting phenotypes of putative proprioceptive and nociceptive trigeminal neurons innervating jaw muscle in rat

BACKGROUND: Despite the clinical significance of muscle pain, and the extensive investigation of the properties of muscle afferent fibers, there has been little study of the ion channels on sensory neurons that innervate muscle. In this study, we have fluorescently tagged sensory neurons that innervate the masseter muscle, which is unique because cell bodies for its muscle spindles are in a brainstem nucleus (mesencephalic nucleus of the 5(th )cranial nerve, MeV) while all its other sensory afferents are in the trigeminal ganglion (TG). We examine the hypothesis that certain molecules proposed to be used selectively by nociceptors fail to express on muscle spindles afferents but appear on other afferents from the same muscle. RESULTS: MeV muscle afferents perfectly fit expectations of cells with a non-nociceptive sensory modality: Opiates failed to inhibit calcium channel currents (I(Ca)) in 90% of MeV neurons, although I(Ca )were inhibited by GABA(B )receptor activation. All MeV afferents had brief (1 msec) action potentials driven solely by tetrodotoxin (TTX)-sensitive Na channels and no MeV afferent expressed either of three ion channels (TRPV1, P2X3, and ASIC3) thought to be transducers for nociceptive stimuli, although they did express other ATP and acid-sensing channels. Trigeminal masseter afferents were much more diverse. Virtually all of them expressed at least one, and often several, of the three putative nociceptive transducer channels, but the mix varied from cell to cell. Calcium currents in 80% of the neurons were measurably inhibited by μ-opioids, but the extent of inhibition varied greatly. Almost all TG masseter afferents expressed some TTX-insensitive sodium currents, but the amount compared to TTX sensitive sodium current varied, as did the duration of action potentials. CONCLUSION: Most masseter muscle afferents that are not muscle spindle afferents express molecules that are considered characteristic of nociceptors, but these putative muscle nociceptors are molecularly diverse. This heterogeneity may reflect the mixture of metabosensitive afferents which can also signal noxious stimuli and purely nociceptive afferents characteristic of muscle