Optogenetic manipulation of stomatal kinetics improves carbon assimilation, water use, and growth

Stomata serve dual and often conflicting roles, facilitating carbon dioxide influx into the plant leaf for photosynthesis and restricting water efflux via transpiration. Strategies for reducing transpiration without incurring a cost for photosynthesis must circumvent this inherent coupling of carbon dioxide and water vapor diffusion. We expressed the synthetic, light-gated K+ channel BLINK1 in guard cells surrounding stomatal pores in Arabidopsis to enhance the solute fluxes that drive stomatal aperture. BLINK1 introduced a K+ conductance and accelerated both stomatal opening under light exposure and closing after irradiation. Integrated over the growth period, BLINK1 drove a 2.2-fold increase in biomass in fluctuating light without cost in water use by the plant. Thus, we demonstrate the potential of enhancing stomatal kinetics to improve water use efficiency without penalty in carbon fixation

About the stability of the dodecatoplet

A new investigation is done of the possibility of binding the "dodecatoplet", a system of six top quarks and six top antiquarks, using the Yukawa potential mediated by Higgs exchange. A simple variational method gives a upper bound close to that recently estimated in a mean-field calculation. It is supplemented by a lower bound provided by identities among the Hamiltonians describing the system and its subsystems.Comment: 5 pages, two figures merged, refs. added, typos correcte

Multiple scattering and attenuation corrections in Deep Inelastic Neutron Scattering experiments

Multiple scattering and attenuation corrections in Deep Inelastic Neutron Scattering experiments are analyzed. The theoretical basis is stated, and a Monte Carlo procedure to perform the calculation is presented. The results are compared with experimental data. The importance of the accuracy in the description of the experimental parameters is tested, and the implications of the present results on the data analysis procedures is examined.Comment: 19 pages, 8 figure

Producing and Detecting Correlated atoms

We discuss experiments to produce and detect atom correlations in a degenerate or nearly degenerate gas of neutral atoms. First we treat the atomic analog of the celebrated Hanbury Brown Twiss experiment, in which atom correlations result simply from interference effects without any atom interactions.We have performed this experiment for both bosons and fermions. Next we show how atom interactions produce correlated atoms using the atomic analog of spontaneous four-wavemixing. Finally, we briefly mention experiments on a one dimensional gas on an atom chip in which correlation effects due to both interference and interactions have been observed.Comment: to appear in conference proceedings "Atomic Physics 20

THE INTERPLAY OF THE K+K- ATOM AND THE f_0(975) RESONANCE

We predict that production of the K+K- atom in pd-3^HeX and similar reactions exhibits a drastic missing mass spectrum due to the interplay with f_0(975) resonance. We point out that high precision studies of the K+K- atom may shed a new light on the nature of f_0(975).Comment: 13 page

Measurements of S and P-A Using the 12-C(p,p'y) Reaction at 150 MeV

This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit

Hadronic Parity Violation and Inelastic Electron-Deuteron Scattering

We compute contributions to the parity-violating (PV) inelastic electron-deuteron scattering asymmetry arising from hadronic PV. While hadronic PV effects can be relatively important in PV threshold electro- disintegration, we find that they are highly suppressed at quasielastic kinematics. The interpretation of the PV quasielastic asymmetry is, thus, largely unaffected by hadronic PV.Comment: 27 pages, 13 figures, uses REVTeX and BibTe

From Majorana theory of atomic autoionization to Feshbach resonances in high temperature superconductors

The Ettore Majorana paper - Theory of incomplete P triplets- published in 1931, focuses on the role of selection rules for the non-radiative decay of two electron excitations in atomic spectra, involving the configuration interaction between discrete and continuum channels. This work is a key step for understanding the 1935 work of Ugo Fano on the asymmetric lineshape of two electron excitations and the 1958 Herman Feshbach paper on the shape resonances in nuclear scattering arising from configuration interaction between many different scattering channels. The Feshbach resonances are today of high scientific interest in many different fields and in particular for ultracold gases and high Tc superconductivity.Comment: 13 pages, 7 figures. Journal of Superconductivity and Novel Magnetism to be publishe

Thermal and electromagnetic properties of 166-Er and 167-Er

The primary gamma-ray spectra of 166-Er and 167-Er are deduced from the (3-He,alpha gamma) and (3-He,3-He' gamma) reaction, respectively, enabling a simultaneous extraction of the level density and the gamma-ray strength function. Entropy, temperature and heat capacity are deduced from the level density within the micro-canonical and the canonical ensemble, displaying signals of a phase-like transition from the pair-correlated ground state to an uncorrelated state at Tc=0.5 MeV. The gamma-ray strength function displays a bump around E-gamma=3 MeV, interpreted as the pygmy resonance.Comment: 21 pages including 2 tables and 11 figure

Reaction rate for two--neutron capture by 4^4He

Recent investigations suggest that the neutrino--heated hot bubble between the nascent neutron star and the overlying stellar mantle of a type--II supernova may be the site of the r--process. In the preceding $\alpha$--process building up the elements to $A \approx 100$, the $^4$He(2n,$\gamma$)$^6$He-- and $^6$He($\alpha$,n)$^9$Be--reactions bridging the instability gap at $A=5$ and $A=8$ could be of relevance. We suggest a mechanism for $^4$He(2n,$\gamma$)$^6$He and calculate the reaction rate within the $\alpha$+n+n approach. The value obtained is about a factor 1.6 smaller than the one obtained recently in the simpler direct--capture model, but is at least three order of magnitude enhanced compared to the previously adopted value. Our calculation confirms the result of the direct--capture calculation that under representative conditions in the $\alpha$--process the reaction path proceeding through $^6$He is negligible compared to $^4$He($\alpha$n,$\gamma$)$^9$Be.Comment: 13 pages, 4 postscript figures, to appear in "Zeitschrift f. Physik A", changed internet address and filename, the uuencoded postscript file including the figures is available at ftp://is1.kph.tuwien.ac.at/pub/ohu/twoneutron.u