Variability and uncertainty in masking by competing speech

This study investigated the role of uncertainty in masking of speech by interfering speech. Target stimuli were nonsense sentences recorded by a female talker. Masking sentences were recorded from ten female talkers and combined into pairs. Listeners' recognition performance was measured with both target and masker presented from a front loudspeaker (nonspatial condition) or with a masker presented from two loudspeakers, with the right leading the front by 4 ms (spatial condition). In Experiment 1, the sentences were presented in blocks in which the masking talkers, spatial configuration, and signal-to-noise (S-N) ratio were fixed. Listeners' recognition performance varied widely among the masking talkers in the nonspatial condition, much less so in the spatial condition. This result was attributed to variation in effectiveness of informational masking in the nonspatial condition. The second experiment increased uncertainty by randomizing masking talkers and S-N ratios across trials in some conditions, and reduced uncertainty by presenting the same token of masker across trials in other conditions. These variations in masker uncertainty had relatively small effects on speech recognition.     

Lie-optics, geometrical phase and nonlinear dynamics of self-focusing and soliton evolution in a plasma

It is useful to state propagation laws for a self-focusing laser beam or a soliton in group-theoretical form to be called Lie-optical form for being able to predict self-focusing dynamics conveniently and amongst other things, the geometrical phase. It is shown that the propagation of the gaussian laser beam is governed by a rotation group in a non-absorbing medium and by the Lorentz group in an absorbing medium if the additional symmetry of paraxial propagation is imposed on the laser beam. This latter symmetry, however, needs care in its implementation because the electromagnetic wave of the laser sees a different refractive index profile than the laboratory observer in this approximation. It is explained how to estimate this non-Taylor paraxial power series approximation. The group theoretical laws so-stated are used to predict the geometrical or Berry phase of the laser beam by a technique developed by one of us elsewhere. The group-theoretical Lie-optic (or ABCD) laws are also useful in predicting the laser behavior in a more complex optical arrangement like in a laser cavity etc. The nonlinear dynamical consequences of these laws for long distance (or time) predictions are also dealt with. Ergodic dynamics of an ensemble of laser beams on the torus during absorptionless self-focusing is discussed in this context. From the point of view of new physics concepts, we introduce a stroboscopic invariant torus and a stroboscopic generating function in classical mechanics that is useful for long-distance predictions of absorptionless self-focusing.     

Synthesis and characterization of titanates of the formula MTiO3 (M = Mn,Fe, Co,Ni and Cd) by co-precipitation of mixed metal oxalates

When divalent metal chloride solutions of Mn, Fe, Co, Ni and Cd were mixed with potassium titanyl oxalate solution, mixed metal oxalates were obtained in the case of Fe, Co and Ni at room temperature in the pH range 1.5–3. In the case of manganese, heating was found to be necessary to induce precipitation and complete precipitation occurred at 80 °C. Mixed cadmium and titanyl oxalate precipitation was complete at a pH of 3 at room temperature. Various physico-chemical techniques were employed to characterize the as-dried oxalate precursors and the final MTiO₃ oxide powders (M = Mn, Fe, Co, Ni and Cd) obtained on thermal decomposition. All these experimental results relating to the synthesis and characterizations of MTiO₃ oxides are presented in this paper. The results suggest that the reaction of potassium titanyl oxalate and metal chloride solutions may not lead to the formation of a single molecular precursor by direct salt elimination reaction in the pH range 1.5–3.     

Chern–Simons classes for a superconnection

In this note we define the Chern–Simons classes of a flat superconnection, D+L$D+L$, on a complex Z/2Z$\mathbb{Z}/2\mathbb{Z}$-graded vector bundle E$E$ on a manifold such that D$D$ preserves the grading and L$L$ is an odd endomorphism of E$E$. As an application, we obtain a definition of Chern–Simons classes of a (not necessarily flat) morphism between flat vector bundles on a smooth manifold. An application of Reznikov's theorem shows the triviality of these classes when the manifold is a compact Kähler manifold or a smooth complex quasi-projective variety in degrees >1$>1$.     

The square-planar cytotoxic [Cu(II)(pyrimol)Cl] complex acts as an efficient DNA cleaver without reductant

Chemical nucleases based on the transition-metal ions cleave DNA hydrolytically and/or oxidatively, with or without added reductant. We report here the novel DNA cleavage properties of the highly water-soluble, square-planar [Cu(Hpyrimol)Cl] complex, together with the results of cytotoxicities toward selected cancer cell lines. The copper complex cleaves PhiX174 supercoiled DNA efficiently without any reductant and shows high cytotoxicities toward L1210 murine leukemia and A2780 human ovarian carcinoma cancer cell lines that are sensitive and resistant to cisplatin. The IC50 values obtained for the copper complex in the sensitive cell lines are in the range of cisplatin, and for the cisplatin-resistant leukemia cell line, this value is even better.     

Iodobenzene diacetate on alumina: Efficient synthesis of 1,3,4‐oxadiazolyl‐1,8‐naphthyridines in solventless system using microwaves

1‐(5‐Aryl‐[1,3,4]oxadiazol‐2‐ylmethyl)‐3‐(p‐methoxyphenyl)‐1H‐[1,8]naphthyridin‐2‐ones ( 5 ) were synthesized by the oxidative cyclization of [2‐oxo‐3‐(p‐methoxyphenyl)‐2H‐[1,8]naphthyridin‐1‐yl]acetic acid arylidene‐hydrazides ( 4 ) with alumina‐supported iodobenzene diacetate (IBD) in solvent‐free conditions under microwave irradiation. The products are obtained in good yields and in a state of high purity.     

An Efficient Green Synthesis of a New Class of α‐Aminophosphonates under Microwave Irradiation Conditions in the Presence of PS/PTSA

The present work focuses on the study of catalytic activity of polystyrene‐supported p‐toluenesulfonic acid (PS/PTSA) and the synthesis of α‐aminophosphonates from the Kabachnik–Fields (KF) reaction under microwave irradiation in solvent‐free conditions. Recently, the catalytic activity of PS/PTSA was tested with good yields. This procedure is the simplest, most straightforward, environment friendly method for the synthesis of α‐aminophosphonates from simple to different substituted aldehyde substrates. Furthermore, this catalyst can be recovered and reused without loss of its catalytic activity.     

Current–voltage characteristics of PLD grown manganite based ZnO/La0.5Pr0.2Sr0.3MnO3/SrNb0.002Ti0.998O3 thin film heterostructure

We report the results of studies on the rectifying behavior and tunneling conduction in ZnO(n)/La_0.5Pr_0.2Sr_0.3MnO₃(LPSMO)(p)/SrNb_0.002Ti_0.998O₃ (SNTO)(n) thin film heterostructure comprising of two p–n junctions fabricated using the Pulsed Laser Deposition (PLD) technique. A structural study using XRD $?$-scan depicts the single-crystalline nature and confirms the phase purity while the transport studies using $I\text{–}V$ measurements at various temperatures and fields reveal the rectifying behavior. The temperature and field dependent variation in the saturation voltage $\left(V_C\right)$ indicates that, the heterostructure exhibits negative magnetoresistance (MR) at low temperatures and positive MR at room temperature (RT) which can be understood on the basis of the interface effect at the junction. $I\text{–}V$ curves obtained at all temperatures and fields show noticeable hysteresis during the positive voltage sweeping which has been attributed to the presence of the various conduction phenomena through the junctions in the presently studied heterostructure.     

Synthesis and antiosteoclast activity of Di(1‐oxo/thioxoperhydro‐1λ5‐[1,3,2] diazaphospholo [1,5‐a]pyridine‐1‐yl) (4‐substituted phenyl) boronates

A new family of di(1‐oxo/thioxoper‐hydro‐1λ⁵‐[1,3,2]diazaphospholo[1,5‐a]pyridine‐1‐yl)(4‐substituted phenyl) boronates ( 4a – j ) has been synthesized in a two‐step process. A reaction of (±)‐piperidin‐2‐yl‐methanamine ( 1 ) phosphoryl/phosphorothioyl chloride in the presence of triethylamine in dry tetrahydrofuran formed the intermediate monochloride ( 2 ), which on condensation with p‐substituted phenylboronic acids ( 3a – j ) afforded the titled compounds ( 4a – j ). They were characterized by elemental, IR, ¹H, ¹³C, ³¹P NMR, and mass spectral analyses. All these compounds showed moderate to high antiosteoclast and osteoblast activity. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:247–253, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21010