Phylogeny and biogeography of ratite birds inferred from DNA sequences of the mitochondrial ribosomal genes

The origin of the flightless ratite birds of the southern continents has been debated for over a century. Whether dispersal or vicariance (continental breakup) best explains their origin depends largely on their phylogenetic relationships. No consensus has been reached on this issue despite many morphological and molecular studies. To address this question further we sequenced a 2.8-kb region of mitochondrial DNA containing the ribosomal genes in representative ratites and a tinamou. Phylogenetic analyses indicate that Struthio (Africa) is basal and Rhea (South America) clusters with living Australasian ratites. This phylogeny agrees with transferrin and DNA hybridization studies but not with sequence analyses of some protein-coding genes. These results also require reevaluation of the phylogenetic position of the extinct moas of New Zealand. We propose a new hypothesis for the origin of ratites that combines elements of dispersal and vicariance.      

Regiospecific C(naphthyl)-H bond activation: Isolation and characterization of cyclopalladates

In ethanol medium disodium tetrachloropalladate selectively activates the C8-H bond of naphthyl group present in 1-(2′-hydroxy-5′-methylphenylazo)naphthalene(H₂L¹) at room temperature and produces cyclometallate [PdL¹(PPh₃)] in presence of triphenylphosphine. Under similar reaction condition, the C(naphthyl)-H bond activation of 1-(2′-methoxy-5′-methylphenylazo)naphthalene (HL²) occurs at C2 and cyclopalladate [PdL²Cl] has been isolated as product. The labile nature of the Pd ←:O(R) bond of [PdL²Cl] in solution is established from the electronic and NMR spectra. Cyclopalladate [PdL²Cl] reacts with thallium(I) cyclopentadienide and yields [PdL²(Cp)], where both σ- and π-palladium(II)-carbon bonds exist. All the cyclopalladates have been isolated in pure form and characterized on the basis of their spectral data. The molecular structure of cyclopalladate [PdL¹(PPh₃)] has been determined by single crystal X-ray diffraction method. In [PdL¹(PPh₃)], the metal ion is bonded to C8 (peri-position of 1-azonaphthyl fagment), N1 of diazene function, O1 of phenolic group and P1 of triphenylphosphine. The tetra-coordination around palladium(II) is in a distorted square-planar geometry.     

Synthesis of HPMC stabilized nickel nanoparticles and investigation of their magnetic and catalytic properties

Nickel nanoparticles synthesized from NiCl₂·6H₂O by hydrazine hydrate in mixed solvent of ethanol and water in the presence of hydroxypropylmethylcellulose (HPMC) as protective and stabilizing agents. The morphology and sizes of synthesized Ni nanoparticles were studied by field-emission-scanning-electron microscopy (FESEM). Structural properties of nanoparticles were examined by X-ray diffraction (XRD). The polymer stabilized Ni nanoparticles were characterized by Fourier-transform infrared (FTIR) spectroscopy. The magnetic measurement showed that the resultant Ni nanoparticles were ferromagnetic. Also, the saturation magnetization (M_S), remanent magnetization (M_R) and coercivity (M_R) were observed to increase with decreasing temperature. The results of magnetic characterization showed that the magnetic properties of the HPMC stabilized Ni nanoparticles are quite different from those of the bared Ni nanoparticles. All the observed magnetic properties essentially reflected the very typical nanoparticle type nature. Consequently, the resulting Ni nanoparticles were found to be highly active and recyclable catalyst for Suzuki coupling reactions.     

Types of interaction of meso‐tetraphenylporphyrin with alkali and alkaline‐earth metal ions

The cavity in a porphyrin can accommodate metal ions through electron donor–acceptor (EDA) interaction in acetonitrile media without any specially designed fabrication with the porphyrin subunit. Alkali metal ion forms a complex with meso‐tetraphenylporphyrin (TP) in 2:1 stoichiometry, while the bivalent Mg²⁺ ion follows a 1:1 stoichiometry. A fluorescence interaction study indicated that TP can behave like a chemosensor for these ions present in the blood electrolytes. Specifically, for the alkali metal ions intensity‐based sensing was observed, due to inhibition of photoinduced electron transfer (PET), entailing enhancement of fluorescence intensity, and for the alkaline‐earth Mg²⁺ a mixed quenching was observed. Na⁺ and K⁺ ions can be differentiated depending upon the extent of fluorescence enhancement. Copyright © 2011 John Wiley & Sons, Ltd.     

Ethnobotany of some weeds of Khasi and Garo Hills,Meghalaya, Northeastern India

Meghalaya, one of the seven states of northeastern India, is inhabited by three distinct tribes, viz., Khasi, Garo, and Jaintia, each occupying respective districts. These tribes live in remote places and depend mostly on surrounding plant resources for their food, shelter, fodder, medicare, and other cultural purposes. Local hill agricultural practice—“slash-and-burn”—and encroaching civilization are responsible for diminishing the local uses of the plants. Hence, it was felt worthwhile to record the native uses of these weeds before the information is buried. The present paper deals with the ethnobotany of 65 taxa belonging to 26 families ofangiosperms. A generic index is included.