Diversification as a Value-Adding Strategy for Asian REITs: A Myth or Reality?

This study tests the impact of diversification strategies on the cash flows, expenses, risks and returns of REITs in Asia. Hirschman-Herfindahl indices (HHI) are computed based on 2281 properties owned by 63 sample Asian REITs for the periods from 2002 to 2007 to measure the levels of diversification by property type and geographical region. In our empirical tests that use weighted least square regressions, we find no significant effects of diversification by property types on cash flows, expenses and risk premiums of Asian REITs. However, significant variations in expenses and risk premiums of the REITs are explained by a geographical diversification strategy. REITs with assets distributed across different countries incur higher total expenses, interest expenses, general and administrative expenses and capital expenditure. Regionally diversified REITs have higher risk premiums. The results remain unchanged after controlling for country factor and simultaneity between the cash flows, expenses, risk and return variables.Diversification and focus strategies; Asian REITs; Illiquidity premiums

Superconductivity Phase Diagram of Na(x)CoO(2).1.3H(2)O

Although the microscopic origin of the superconductivity in high Tc copper oxides remains the subject of active inquiry, several of their electronic characteristics are well established as universal to all the known materials, forming the experimental foundation that all theories must address. The most fundamental of those characteristics is the dependence of the superconducting transition temperature on the degree of electronic band filling. Since the discovery of cuprate superconductivity in 1986 (1), the search for other families of superconductors that might help shed light on the superconducting mechanism of the cuprates has been of great interest. The recent report of superconductivity near 4K in the triangular lattice, layered sodium cobalt oxyhydrate, Na0.35CoO2.1.3H2O, is the best indication that superconductors related to the cuprates may be found (2). Here we show that the superconducting transition temperature of this compound displays the same kind of band-filling behavior that is observed in the cuprates. Specifically, that the optimal superconducting Tc occurs in a narrow range of band filling, and decreases for both underdoped and overdoped materials, in dramatic analogy to the phase diagram of the cuprate superconductors. Our results suggest that characterization of the detailed electronic and magnetic behavior of these new materials may help establish which of the many special characteristics of the cuprates is fundamental to their high Tc superconductivity.Comment: revised, publication information adde

Cost-consequence analysis for human recombinant growth hormone (r-hGH) treatment administered via different devices in children with growth hormone deficiency in Italy

Background: The objective of this analysis was to evaluate the cost-consequence of recombinant human growth hormone (r-hGH) administered via the easypod auto-injector (Merck, Darmstadt, Germany) versus conventional devices in children with growth hormone deficiency in Italy. Methods: A patient-level simulation, decision-analytical model was developed to estimate the average height gains and growth hormone treatment costs for a cohort of boys and girls until their bone maturation age. The calculations were performed using listed growth hormone drug prices (base case) and a scenario analysis was also conducted using published tender prices. Costs were discounted at 3%. Results: Due to improved adherence and earlier identification of poor responders, patients receiving somatropin with easypod gained, on average, 3.2 cm more than patients receiving other r-hGH treatments. Somatropin with easypod had the second highest total cost including wastage (\u20ac96,710), but had the second lowest cost per cm gained (\u20ac7699/cm). In the scenario analysis, somatropin with easypod had the lowest cost per cm gained (\u20ac4708/cm) amongst all of the compared treatments. Conclusion: Somatropin with easypod can be cost-saving versus all other r-hGH treatments except Omnitrope when listed drug prices are considered and can be cost-saving versus all other r-hGH treatments when tender drug prices are considered. The easypod device also facilitates cost savings in terms of reduced wastage

Novel phase diagram of superconductor NaxCoO2-yH2O in a 75 % relative humidity

We succeeded in synthesizing the powder samples of bilayer-hydrate sodium cobalt oxide superconductors NaxCoO2-yH2O with Tc = 0 ~ 4.6 K by systematically changing the keeping duration in a 75 % relative humidity atmosphere after intercalation of water molecules. From the magnetic measurements, we found that the one-day duration sample does not show any superconductivity down to 1.8 K, and that the samples kept for 2 ~ 7 days show superconductivity, in which Tc increases up to 4.6 K with increasing the duration. Tc and the superconducting volume fraction are almost invariant between 7 days and 1month duration. The 59Co NQR spectra indicate a systematic change in the local charge distribution on the CoO2 plane with change in duration.Comment: 4 pages, 5 figures, submitted to Journal of the Physical Society of Japa

Large enhancement of the thermopower in Nax_xCoO2_2 at high Na doping

Research on the oxide perovskites has uncovered electronic properties that are strikingly enhanced compared with those in conventional metals. Examples are the high critical temperatures of the cuprate superconductors and the colossal magnetoresistance in the manganites. The conducting layered cobaltate $\rm Na_xCoO_2$ displays several interesting electronic phases as $x$ is varied including water-induced superconductivity and an insulating state that is destroyed by field. Initial measurements showed that, in the as-grown composition, $\rm Na_xCoO_2$ displays moderately large thermopower $S$ and conductivity $\sigma$. However, the prospects for thermoelectric cooling applications faded when the figure of merit $Z$ was found to be small at this composition (0.6$<x<$0.7). Here we report that, in the poorly-explored high-doping region $x>$0.75, $S$ undergoes an even steeper enhancement. At the critical doping $x_p\sim$ 0.85, $Z$ (at 80 K) reaches values $\sim$40 times larger than in the as-grown crystals. We discuss prospects for low-temperature thermoelectric applications.Comment: 6 pages, 7 figure

Magnetic and Metal-Insulator Transitions in beta-Na0.5CoO2 and gamma-K0.5CoO2 -NMR and Neutron Diffraction Studies-

Co-oxides beta-Na0.5CoO2 and gamma-K0.5CoO2 have been prepared by the Na de-intercalation from alpha-NaCoO2 and by the floating-zone method, respectively. It has been found that successive phase transitions take place at temperatures Tc1 and Tc2 in both systems. The appearance of the internal magnetic field at Tc1 with decreasing temperature T indicates that the antiferromagnetic order exists at T < Tc1, as in gamma-Na0.5CoO2. For beta-Na0.5CoO2, the transition temperatures and the NMR parameters determined from the data taken for magnetically ordered state are similar to those of gamma-Na0.5CoO2, indicating that the difference of the stacking ways of the CoO2 layers between these systems do not significantly affect their physical properties. For gamma-K0.5CoO2, the quantitative difference of the physical quantities are found from those of beta- and gamma-Na0.5CoO2. The difference between the values of Tci (i = 1 and 2) of these systems might be explained by considering the distance between CoO2 layers.Comment: 8 pages, 14 figures, 1 Tabl

Thermal and Electrical Properties of gamma-NaxCoO2 (0.70 < x < 0.78)

We have performed specific heat and electric resistivity measurements of Na$_{x}$CoO$_{2}$ ($x=0.70$-0.78). Two anomalies have been observed in the specific heat data for $x=0.78$, corresponding to magnetic transitions at $T_{c}=22$ K and $T_{k}\simeq 9$ K reported previously. In the electrical resistivity, a steep decrease at $T_{c}$ and a bending-like variation at $T_{b}$(=120K for $x=0.78$) have been observed. Moreover, we have investigated the $x$-dependence of these parameters in detail. The physical properties of this system are very sensitive to $x$, and the inconsistent results of previous reports can be explained by a small difference in $x$. Furthermore, for a higher $x$ value, a phase separation into Na-rich and Na-poor domains occurs as we previously proposed, while for a lower $x$ value, from characteristic behaviors of the specific heat and the electrical resistivity at the low-temperature region, the system is expected to be in the vicinity of the magnetic instability which virtually exists below $x=0.70$.Comment: 4 pages (3 figures included) and an extra figure (gif), to be published in J. Phys. Soc. Jpn. 73 (9) with possible minor revision

Improved pre-treatment protocol for scanning electron microscopy coupled with energy dispersive X-ray spectroscopy analysis of selected tropical microalgae

Suitable protocol for identification and classification of microalgae using scanning electron microscopy, coupled with energy dispersive X-ray spectroscopy (SEM-EDX), is important to obtain accurate information of their ultrastructure description. The objective of this study was to modify microalgae pre-treatments for reliable SEM-EDX analysis. Sixteen cultured tropical microalgae were subjected to two-step chemical fixation of glutaraldehyde and osmium tetroxide, sample washing in sodium cacodylate, ethanol and acetone dehydration, critical point-drying, mounting and gold sputter-coating prior to SEM visualisation and elemental characterisation. In this study, short period of chemical fixation and optimum separation forces, at 3213 x g for 3 min during every chemical solution change, were successfully established with high quality SEM images. Ultrastructure, particularly clear and useful images of cell wall ornamentation in Scenedesmus spp. and Desmodesmus sp.; areola patterns in Biddulphia sinensis and Thalassiosira sp. and morphological appearances such as interconnecting structures in Coelastrum sp. and Crucigenia sp., were obtained. Twelve elements of Y, Nb, Fe, Ca, Cl, K, Cu, F, Ir, P, Mg and Si were detected within the 16 investigated microalgae species. This study illustrated that microalgae identification and classification, as well as their elemental characterisation, could be simultaneously and effectively analysed by SEM-EDX using a modified pre-treatment protocol

Coupling between electronic and structural degrees of freedom in the triangular lattice conductor NaxCoO2

The determination by powder neutron diffraction of the ambient temperature crystal structures of compounds in the NaxCoO2 family, for 0.3 < x <= 1.0, is reported. The structures consist of triangular CoO2 layers with Na ions distributed in intervening charge reservoir layers. The shapes of the CoO6 octahedra that make up the CoO2 layers are found to be critically dependent on the electron count and on the distribution of the Na ions in the intervening layers, where two types of Na sites are available. Correlation of the shapes of cobalt-oxygen octahedra, the Na ion positions, and the electronic phase diagram in NaxCoO2 is made, showing how structural and electronic degrees of freedom can be coupled in electrically conducting triangular lattice systems.Comment: 15 pages, 1 tables, 6 figures Submitted to Physical Review