Spectroscopy inside the homogeneous linewidth in three-coupled level system

Features narrower than the two-levels homogeneous linewidths can occur in laser-saturation spectroscopy experiments on three levels systems. They are described and demonstrated on vibrational-rotational molecular spectra.     

13CH3OH and13CD3OH optically pumped fir laser: New large offset emission and optoacoustic spectroscopy

27 new, large offset, FIR laser lines from¹³CH₃OH and one from¹³CD₃OH have been discovered by pumping with a high tunability waveguide CW CO₂ laser. Optoacoustic measurements of isotopic methyl alcohol have also been performed and the pump offsets of the new and of previously known lines have been measured and checked. Frequency tunability by Stark effect has been observed for 6 strong lines. Some assignments are discussed.     

Connection problems in mountains and monotonic allocation schemes

Directed minimum cost spanning tree problems of a special kind are studied, namely those which show up in considering the problem of connecting units (houses) in mountains with a purifier. For such problems an easy method is described to obtain a minimum cost spanning tree. The related cost sharing problem is tackled by considering the corresponding cooperative cost game with the units as players and also the related connection games, for each unit one. The cores of the connection games have a simple structure and each core element can be extended to a population monotonic allocation scheme (pmas) and also to a bi-monotonic allocation scheme. These pmas-es for the connection games result in pmas-es for the cost game.     

The development of a membrane-based screening method to detect antibodies to intermediate filament proteins.

Autoantibodies directed against the intermediate filament proteins (IF) arise in a variety of disease states. The authors have investigated the binding of the IF to solid membrane supports in a dot blot format in an attempt to develop a simple procedure to detect antibodies (ab) to IF. Commercially obtained, purified IF were utilized. These were: vimentin (VIM), cytokeratin 8 (CYK), glial fibrillary acidic protein (GFA), desmin (DES), and the neurofilament triplet proteins (68, 160, and 200 KDa, respectively designated LMW, MMW, and HMW). Murine monoclonal antibody (mAb) probes were used to detect the presence and immunoreactivity of IF. The mAb were visualized with HRP-anti-mouse conjugates using alpha-chloronaphthol/H 2O 2 as substrate. The membranes studied were nitrocellulose (NC), and two of modified nylon. Nitrocellulose provided the most reproducible binding; no advantage was found to ensue from the use of the other membranes with regard either to quantitative binding or improved capping. Among the IF studied, VIM, GFA, LMW, MMW, and HMW bound well to NC; optimal mass/dot was 1 mug. Filtered, non-fat dry milk is a better capping agent than either albumin or fetal calf serum, but interferes with ab binding to GFA. Binding of CYK and DES is weak at neutral pH. Standard densitometric techniques provide the possibility of quantitation. We conclude that dot and slot blot assays may be practical methods to detect ab to IF antigens.     

Trying to catch the elusive A and more. Reactions initiated by b-quarks and the Higgs sector of the MSSM

We study the cross sections for the production of neneural, intermediate mass Higgs boson in the process pp→ tq′φ, pp→tW⁻φ and pp→bZ⁰φ in the Minimal Supersymmetric Standard Model (φ = H⁰, h⁰ and A⁰) at Supercollider energies. The additional heavy particles (t, W, Z) in the final state can be used for tagging purposes, increasing the signal to background ratio. These reactions are dominated by bg and bg fusion. Their relevance for Higgs particle searches is discussed taking into account the expected efficiencies and purities for b-tagging. We find that, for tan β = 30, the cross sections for pp → bZ⁰φ are larger than 14 pb, over the whole intemediate range of M_A⁰, for A⁰ and at least one of the other two Higgses. Therefore this reaction is an excellent candidate for the discovery of one or more MSSM Higgs particles.     

Relationship between the auger parameter and the energy gap

In this communication we show that for different semiconductors which do not contain transition metal ions, the shift in the extra-atomic relaxation energy for the metal ion with the core hole-as measured by the Wagner Auger parameter shift with respect to the metallic state-is roughly linearly correlated to the energy gap with a slope approximately equal to −1. The relationship, useful from a practical point of view, can be rationalized using the qualitative concepts of local and non-local screening developed by Veal and Paulikas and the direct relation between the band gap and anion electronegativity.

The core-hole screening for the semiconductors that follow the correlation can be described by the non-local screening mechanism. In this case, the polarized ligands transfer electronic charge to the unfilled s-p metal orbitals which are pulled down to the energy level of the local anion valence band by the core hole. Semiconductors containing transition metal ions, for which local screening mechanisms can occur by transferring the charge from the ligands to the localized d electronic levels, do not follow the correlation. This is due to the fact that the Auger parameter of the cation in the compound is similar to that of the atom in the metallic state. This result indicates that the relaxation energy in the transition metal compounds can be similar to the screening energy in the metallic state.     

Isolation and structure (x-ray analysis) of karinolide,a new quassinoid from Simaba Multiflora

Karinolide $\text{1}$ is a structurally novel C₂₀ quassinoid isolated from the French Guyanan Simaroubaceae, Simaba multiflora A.Juss. whose structure was established by X-ray diffraction analysis. 6α-Senecioyloxychaparrin $\text{2}$, the known 6α-senecioloyxychaparrinone $\text{3}$ and 9-methoxycanthin-6-one $\text{5}$ were also isolated ; their structure were determined by spectral means.