H_3^{++}$ molecular ion in a strong magnetic field: triangular configuration

The existence of the molecular ion $H_3^{++}$ in a magnetic field in a triangular configuration is revised. Variational method with an optimization of the form of the vector potential (gauge fixing) is used. It is shown that in the range of magnetic fields $10^8 < B < 10^{11} G$ the system $(pppe)$, with protons forming an equilateral triangle perpendicular to magnetic line, has a well-pronounced minimum in the total energy. This configuration is unstable towards decays $H{-atom} + p + p$ and $H_2^+ + p$. Triangular configuration of $H_3^{++}$ complements $H_3^{++}$ in the linear configuration which exists for $B \gtrsim 10^{10} G$.Comment: RevTeX 14 pages, 9 figures, 1 table Physical Review A (accepted

The Effects of Sports Related Head Impact on Balance and Neurocognitive Functions

The goal of this study was to investigate the effects of sports-related head injury on balance, attention, and memory. Reliable differences have been found using measures that directly tap into brain functioning, such as the auditory oddball task combined with EEG recording. We hypothesized that athletes reporting a diagnosed concussion or participation in high-risk sports would have compromised balance and neurocognitive functioning compared to athletes in low risk sports. Forty-five undergraduate participants were identified as either concussed, non-concussed in high-risk sports, or non-concussed in low-risk sports using a survey of athletic history, head trauma and demographics. The Biopac MP36 system, a balance board, and the BESS protocol was used to measure balance. E-prime and a 32 channel electrode EEG system was used to conduct an auditory oddball test and a working-memory task. No significant differences were found between groups for balance or accuracy on the oddball test or working memory task. EEG analysis showed no significance differences in latency (response time) but participants who reported a concussion or participation in a high-risk sport did have significantly lower amplitude (response strength) compared to those in low-risk sports. There was also an inverse correlation between errors in the attention task and amplitude. Consistent with prior research, no differences were found using behavioral measures of attention and memory, but more sensitive EEG measures were able to detect subtle differences between groups

Reduced calcification and lack of acclimatization by coral colonies growing in areas of persistent natural acidification

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 110 (2013):11044-11049, doi:10.1073/pnas.1301589110.As the surface ocean equilibrates with rising atmospheric CO2, the pH of surface seawater is decreasing with potentially negative impacts on coral calcification. A critical question is whether corals will be able to adapt or acclimate to these changes in seawater chemistry. We use high precision CT scanning of skeletal cores of Porites astreoides, an important Caribbean reef-building coral, to show that calcification rates decrease significantly along a natural gradient in pH and aragonite saturation (Ωarag). This decrease is accompanied by an increase in skeletal erosion and predation by boring organisms. The degree of sensitivity to reduced Ωarag measured on our field corals is consistent with that exhibited by the same species in laboratory CO2 manipulation experiments. We conclude that the Porites corals at our field site were not able to acclimatize enough to prevent the impacts of local ocean acidification on their skeletal growth and development, despite spending their entire lifespan in low pH, low Ωarag seawater.This research was funded by Na¬tional Science Foundation (NSF) OCE-1040952, a University of California Institute for Mexico and the United States (UC-Mexus) grant (to A.P.), and NSF OCE-1041106 (to A.L.C.). E.D.C. was funded through NSF-GFR and a EPA-STAR fellowships.2013-12-1

The hydrogen molecule H2\rm{H}_{2} in inclined configuration in a weak magnetic field

Highly accurate variational calculations, based on a few-parameter, physically adequate trial function, are carried out for the hydrogen molecule \hh in inclined configuration, where the molecular axis forms an angle $\theta$ with respect to the direction of a uniform constant magnetic field ${\bf B}$, for $B=0,\, 0.1,\, 0.175$ and $0.2\,$a.u. Three inclinations $\theta=0^\circ,\,45^\circ,\,90^\circ$ are studied in detail with emphasis to the ground state $1_g$. Diamagnetic and paramagnetic susceptibilities are calculated (for $\theta=45^\circ$ for the first time), they are in agreement with the experimental data and with other calculations. For $B=0,\, 0.1$ and $0.2\,$a.u. potential energy curves $E$ vs $R$ are built for each inclination, they are interpolated by simple, two-point Pad\'e approximant $Pade[2/6](R)$ with accuracy of not less than 4 significant digits. Spectra of rovibrational states are calculated for the first time. It was found that the optimal configuration of the ground state for $B \leq B_{cr}=0.178\,$a.u. corresponds always to the parallel configuration, $\theta=0$, thus, it is a $^1\Sigma_g$ state. The state $1_g$ remains bound for any magnetic field, becoming metastable for $B > B_{cr}$, while for $B_{cr} < B < 12$\,a.u. the ground state corresponds to two isolated hydrogen atoms with parallel spins.Comment: 31 pages, 11 Tables, 7 Figures (2 new), following referee's suggestions parts 4,5,6 essentially rewritten, to be published at Journal of Quantitative Spectroscopy and Radiative Transfe

Dystroglycan Depletion Impairs Actin-Dependent Functions of Differentiated Kasumi-1 Cells

Background Dystroglycan has recently been characterised in blood tissue cells, as part of the dystrophin glycoprotein complex involved in the differentiation process of neutrophils. Purpose In the present study we have investigated the role of dystroglycan in the human promyelocytic leukemic cell line Kasumi-1 differentiated to macrophage-like cells. Methods We characterised the pattern expression and subcellular distribution of dystroglycans in non-differentiated and differentiated Kasumi-1 cells. Results Our results demonstrated by WB and flow cytometer assays that during the differentiation process to macrophages, dystroglycans were down-regulated; these results were confirmed with qRT-PCR assays. Additionally, depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated Kasumi-1 cells, including morphology, migration and phagocytic activities although secretion of IL-1β and expression of markers of differentiation are not altered. Conclusion Our findings strongly implicate dystroglycan as a key membrane adhesion protein involved in actin-based structures during the differentiation process in Kasumi-1 cells

One-electron atomic-molecular ions containing Lithium in a strong magnetic field

The one-electron Li-containing Coulomb systems of atomic type $(li, e)$ and molecular type $(li, li, e)$, $(li, \alpha, e)$ and $(li, p, e)$ are studied in the presence of a strong magnetic field $B \leq 10^{7}$ a.u. in the non-relativistic framework. They are considered at the Born-Oppenheimer approximation of zero order (infinitely massive centers) within the parallel configuration (molecular axis parallel to the magnetic field). The variational and Lagrange-mesh methods are employed in complement to each other. It is demonstrated that the molecular systems ${\rm LiH}^{3+}$, ${\rm LiHe}^{4+}$ and ${\rm Li}_{2}^{5+}$ can exist for sufficiently strong magnetic fields $B \gtrsim 10^{4}$ a.u. and that ${\rm Li}_{2}^{5+}$ can even be stable at magnetic fields typical of magnetars.Comment: 22 pages, 9 figures, 4 table

Síntesis y caracterización de fotocatalizadores de TiO2 nanomodificados con Ag para descontaminación de aguas en Santiago del Estero.

Capítulo de libroEn este trabajo se exponen algunos de los avances logrados en la etapa inicial del desarrollo de un nuevo material fotocatalítico, relacionados con su síntesis y modificación de la actividad fotocatalítica.Fil: Monasterio, Fernanda E.. Instituto de Bionanotecnología del NOA, INBIONATEC-CONICET/Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina. Email: [email protected]: Borsarelli, Claudio D.. Instituto de Bionanotecnología del NOA, INBIONATEC-CONICET/Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina.Fil: Morán Vieyra, Faustino E.. Instituto de Bionanotecnología del NOA, INBIONATEC-CONICET/Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina