Functional Diversity of Small and Large Trees Along Secondary Succession in a Tropical Dry Forest

Functional Diversity is considered an important driver of community assembly in environmental and successional gradients. To understand tree assembly processes in a semideciduous tropical forest, we analyzed the variation of Functional Richness (FRic), Functional Divergence (FDiv), and Functional Evenness (FEve) of small vs. large trees in relation to fallow age after slash-and-burn agriculture and topographical position (flat sites vs. hills). FRic of small trees was lower than null model predicted values across the successional gradient, and decreased unexpectedly in older successional ages. FRic of large trees was higher than null model predictions early in succession and lower in late-successional stands on hills. Dominant species were more similar (low FDiv) in early and intermediate successional stands for small trees, and on hills for large trees, suggesting that species that are best adapted to harsh conditions share similar traits. We also found evidence of competitive exclusion among similar species (high FEve) for small trees in early successional stands. Overall, our results indicate that community assembly of small trees is strongly affected by the changing biotic and abiotic conditions along the successional and topographical gradient. For large trees, hills may represent the most stressful conditions in this landscape

Patterns of Plant Functional Variation and Specialization Along Secondary Succession and Topography in a Tropical Dry Forest

Long-term human disturbance of tropical forests may favor generalist plant species leading to biotic homogenization. We aimed to a) assess if generalist species dominate across different successional ages and topographical positions in a tropical dry forest with a long history of human disturbance, b) to characterize functional traits associated with generalist and specialist species, and c) to assess if a predominance of generalists leads to a homogeneous functional structure across the landscape. We used a multinomial model of relative abundances to classify 118 woody species according to their successional/topographic habitat. Three species were classified as secondary-forest specialists, five as mature-forest specialists, 35 as generalists, and 75 as too rare to classify. According to topography, six species were hill specialists, eight flat-site specialists, 35 generalists, and 70 too rare. Generalists dominated across the landscape. Analysis of 14 functional traits from 65 dominant species indicated that generalists varied from acquisitive strategies of light and water early in succession to conservative strategies in older forests and on hills. Long-term human disturbance may have favored generalist species, but this did not result in functional homogenization. Further analyses considering other functional traits, and temporal and fine-scale microenvironmental variation are needed to better understand community assembly

Methicillin Resistant Staphylococcus aureus (MRSA) in market age pigs on-farm, at slaughter and retail pork

This study was conducted to determine the occurrence and prevalence of methicillin resistant Staphylococcus aureus (MRSA) in finishing pigs on-farm, at lairage and assess the likelihood of carriage at slaughter and retail levels. A cross-sectional study targeting ten cohorts of commercial swine farms was conducted for carriage of MRSA

Bremsstrahlung radiation by a tunneling particle

We study the bremsstrahlung radiation of a tunneling charged particle in a time-dependent picture. In particular, we treat the case of bremsstrahlung during alpha-decay, which has been suggested as a promissing tool to investigate the problem of tunneling times. We show deviations of the numerical results from the semiclassical estimates. A standard assumption of a preformed particle inside the well leads to sharp high-frequency lines in the bremsstrahlung emission. These lines correspond to "quantum beats" of the internal part of the wavefunction during tunneling arising from the interference of the neighboring resonances in the well.Comment: 4 pages, 4 figure

Physiological Responses of Species to Microclimate Help explain Population Dynamics along Succession in a Tropical Dry Forest of Yucatan, Mexico

We investigated relationships between population dynamics and microclimate, physiology, and the degree of mycorrhizal colonization, for three species (Piscidia piscipula L.(Sarg.)) (Fabaceae), Bunchosia swartzianaGriseb. (Malpighiaceae) and Psidium sartorianum (Bergius) Nied. (Myrtaceae)) of a tropical sub deciduous forest in Yucatan, Mexico that were growing in plots of different successional ages. We hypothesized that abundance and persistence were related to increased plasticity in CO2assimilation. We found that Piscidia piscipula had greater abundance in intermediate plots (18 to 21 years), presented higher levels of plasticity in CO2 assimilation (greater variability among individuals, plots, and seasons), presented the highest CO2 assimilation rates, and presented greater drought resistance (higher water potentials and capacitance). Conversely, Psidium sartorianum had greater abundance in older plots (more than 50 years of secondary succession), lower assimilation rates, and low levels of plasticity in CO2 assimilation. Bunchosia had intermediate values. Locally, the degree of mycorrhizal colonization was consistent with abundance across plots. Regionally (but not locally), plasticity in CO2 assimilation was consistent with abundance. We found differences in microclimates among plots and within plots among species. Physiological adjustments appeared to play an important role in the capacity to regenerate and in the successional persistence of these species in this tropical dry forest

A novel oxidovanadium(V) compound with an isonicotinohydrazide ligand: A combined experimental and theoretical study and cytotoxity against K562 cells

The interaction of oxidovanadium(V) with INHOVA (the condensation product of isoniazid and o-vanillin) lead to the formation of the ester-like complex [VO(INHOVA)EtO(OH2)]Cl·H2O (1). Crystals suitable for X-ray diffraction methods were obtained. The complex crystallizes as a dimer in the space group P21/c of the monoclinic system. A detailed analysis, including solid-state vibrational spectroscopy and electronic spectroscopy in DMSO solution, was performed for both INHOVA and complex (1). A complete theoretical study based on DFT was also carried out. The calculations were of valuable assistance in the spectra assignments and interpretation. The electrochemical characterization allows determining the redox behavior of INHOVA and complex (1). Cytotoxicity was assayed against the chronic myelogenous leukemia K562 cell line. The IC50 values obtained denote that both the ligand and complex (1) are good candidates for further studies.Fil: Gonzalez Baro, Ana Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica ; ArgentinaFil: Ferraresi Curotto, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica ; ArgentinaFil: Pis Diez, Reinaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica ; ArgentinaFil: Parajón Costa, Beatriz Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica ; ArgentinaFil: Resende, Jackson A. L. C.. Cua/ufmt; . Universidade Federal do Mato Grosso do Sul; BrasilFil: de Paula, Flávia C. S.. Universidade Federal de Minas Gerais; BrasilFil: Pereira Maia, Elene C.. Universidade Federal de Minas Gerais; BrasilFil: Rey, Nicolás A.. Universidade de Sao Paulo; Brasi

A novel oxidovanadium(V) compound with an isonicotinohydrazide ligand: A combined experimental and theoretical study and cytotoxity against K562 cells

The interaction of oxidovanadium(V) with INHOVA (the condensation product of isoniazid and o-vanillin) lead to the formation of the ester-like complex [VO(INHOVA)EtO(OH2)]Cl·H2O (1). Crystals suitable for X-ray diffraction methods were obtained. The complex crystallizes as a dimer in the space group P21/c of the monoclinic system. A detailed analysis, including solid-state vibrational spectroscopy and electronic spectroscopy in DMSO solution, was performed for both INHOVA and complex (1). A complete theoretical study based on DFT was also carried out. The calculations were of valuable assistance in the spectra assignments and interpretation. The electrochemical characterization allows determining the redox behavior of INHOVA and complex (1). Cytotoxicity was assayed against the chronic myelogenous leukemia K562 cell line. The IC50 values obtained denote that both the ligand and complex (1) are good candidates for further studies.Centro de Química Inorgánic

Haploinsufficiency of A20 impairs protein–protein interactome and leads into caspase-8-dependent enhancement of NLRP3 inflammasome activation

Objectives TNFAIP3 encodes A20 that negatively regulates nuclear factor kappa light chain enhancer of activated B cells (NF-κB), the major transcription factor coordinating inflammatory gene expression. TNFAIP3 polymorphisms have been linked with a spectrum of inflammatory and autoimmune diseases and, recently, loss-of-function mutations in A20 were found to cause a novel inflammatory disease ‘haploinsufficiency of A20’ (HA20). Here we describe a family with HA20 caused by a novel TNFAIP3 loss-of-function mutation and elucidate the upstream molecular mechanisms linking HA20 to dysregulation of NF-κB and the related inflammasome pathway.Methods NF-κB activation was studied in a mutation-expressing cell line using luciferase reporter assay. Physical and close-proximity protein–protein interactions of wild-type and TNFAIP3 p.(Lys91*) mutant A20 were analysed using mass spectrometry. NF-κB -dependent transcription, cytokine secretion and inflammasome activation were compared in immune cells of the HA20 patients and control subjects.Results The protein–protein interactome of p.(Lys91*) mutant A20 was severely impaired, including interactions with proteins regulating NF-κB activation, DNA repair responses and the NLR family pyrin domain containing 3 (NLRP3) inflammasome. The p.(Lys91*) mutant A20 failed to suppress NF-κB signalling, which led to increased NF-κB -dependent proinflammatory cytokine transcription. Functional experiments in the HA20 patients’ immune cells uncovered a novel caspase-8-dependent mechanism of NLRP3 inflammasome hyperresponsiveness that mediated the excessive secretion of interleukin-1β and interleukin-18.Conclusions The current findings significantly deepen our understanding of the molecular mechanisms underlying HA20 and other diseases associated with reduced A20 expression or function, paving the way for future therapeutic targeting of the pathway.Peer reviewe

Angular momentum of focused beams: beyond the paraxial approximation

We investigate in detail the focusing of a circularly polarized Laguerre-Gaussian laser beam ($\hbar \ell$ orbital angular momentum per photon; $\sigma=1/-1$ for left/right-handed polarization) by a high numerical aperture objective. The diffraction-limited focused beam has unexpected properties, resulting from a strong interplay between the angular spatial structure and the local polarization in the non-paraxial regime. In the region near the beam axis, and provided that $|\ell|\ge 2$ and $\ell$ and $\sigma$ have opposite signs, the energy locally counter-propagates and the projection of the electric field onto the focal plane counter-rotates with respect to the circular polarization of the incident beam. We explicitly show that the total angular momentum flux per unit power is conserved after focusing, as expected by rotational symmetry, but the spin and orbital separate contributions change.Comment: 10 pages, 9 figure