Boards of Directors and Firm Leverage: Evidence from Real Estate Investment Trusts

We re-examine the negative association between leverage and returns while also focusing on the role of boards of directors. To do so, we utilize the unique setting of real estate investment trusts (REITs), their high leverage, and the volatility that the industry experienced during the recent financial crisis. We find that during the financial crisis REIT board activity increased, especially among firms with high leverage. We also find that board activity helps mitigate the previously reported negative effect of leverage on returns during this time period. Post-crisis, we find evidence suggesting that firms with more active boards reduce their leverage if their pre-crisis leverage was high. Further, firms with more active boards have better post-crisis returns. Our findings are robust to using different measures of activity that take into account director experience in real estate and finance

Étude de prévention de la thrombose veineuse associée au cathéter veineux central de type PICC chez les patients en oncologie recevant une chimiothérapie

Nous avons mené une étude prospective randomisée dans le but de comparer l'effet de l'irrigation du cathéter de type PICC avec deux types d'anticoagulants: Héparine standard et Tinzaparine, une héparine de faible poids moléculaire. Notre étude s'adresse aux patients de la clinique externe d'oncologie de l'hôpital Maisonneuve-Rosemont. Entre début Mai 2005 et Mars 2008, nous avons recruté 131 patients dont 70 ont été randomisés. Parmi les 61 patients exclus, 23 n'ont pas rencontré les critères d'inclusion, 30 ont refusé de participer et 8 ne sont pas inclus pour d'autres raisons. Sur les 70, 36 sujets sont randomisés dans le groupe Héparine standard et 34 dans le groupe Tinzaparine. La population en intention de traiter comprend 65 sujets dont 32 dans le groupe Héparine standard et 33 dans le groupe Tinzaparine. Le médicament a été administré pendant un mombre maximal de 30 jours et les sujets ont été suivis pendant 90 jours. La thrombose veineuse associée au cathéter (TVAC) a été objectivée par une phlébographie ou une échographie-Doppler à la fin de la période de 30 jours suivant l'installation du cathéter. L'incidence de la TVAC sur 30 jours est de 14,39 par 1000 cathéter-jours (IC à 95%:[9,0;19,79]/1000 cathéter-jours ou 41,5% (27/65). L'incidence de la thrombose veineuse profonde (TVP) symptômatique du membre supérieur sur la période de suivi de 90 jours est de 0,41 par 1000 cathéter-jours (IC à 95%:[0,08;0,81]/1000 cathéter-jours ou 3% (2/65). Nous n'avons observé aucune différence entre les deux groupes par rapport à la fréquence de la TVAC ni de la TVP. Nous ne pouvons conclure à une différence dans l'efficacité de la Tinzaparine par rapport à l'Héparine standard dans la prévention de la TVAC.Our prospective, randomized study aims at comparing the effectiveness of two types of heparin used for the instillation of peripherally inserted central catheter (PICC): Standard heparin and Tinzaparin, a low molecular weight heparin. We recruited patients from the ambulatory center of Maisonneuve-Rosemont hospital. Between the beginning of May 2005 and March 2008, 131 patients were enrolled. Of 61 patients excluded, 23 did not satisfy the inclusion criteria, 30 refused to participate and 8 were not enrolled for other reasons. Seventy patients were randomized into two groups, 36 in the Standard heparin group and 34 in the Tinzaparin group. Our population intent-to-treat included 65/70 patients, 32 of these received Standard heparin and 33 received Tinzaparin. The experimental intervention was administered for a maximum of 30 days and all the subjects were followed up for 90 days. The events were documented objectively with a venogram or Doppler ultrasonography by the end of the 30 days following the catheter installation. The incidence of catheter-related venous thrombosis (CRVT) during 30 days of instillation is 14,39/1000 catheter-days (CI 95%:[9,0;19,79]/1000 catheter-days or 41.5% (27/65). The incidence of symptomatic upper extremity deep venous thrombosis (DVT) during the observation period of 90 days is 0,41/1000 catheter-days (CI 95%:[0,08;0,81]/1000 catheter-days or 3% (2/65). We did not observe any difference in the frequency of CRVT or DVT between the two groups. We can not conclude that either Standard heparin or Tinzaparin is more effective in the prevention of CRVT in our population

THE ISSUE OF NATIONALISM IN NATIONAL LITERATURE EDUCATION IN VIETNAM BEFORE 1945 AND THE LESSONS FOR THE AGE OF GLOBALIZATION

In the current globalization context, Viet Nam’s traditional cultural values have had changes. Stemming from that situation, through content analysis of materials on books, newspapers and magazines before 1945, the author studies the issue of national literature education in Viet Nam based on the aspects of language, documents and teaching content, initially draws some lessons from the education of national conciousness in the current international integration process

Excellent luminous flux of WLEDs with flat dual-layer remote phosphor geometry

This paper focuses on the comparison of the luminous flux of two dual-remote phosphor structures named flat dual-remote phosphor (FDRP) and concave dual-remote phosphor (CDRP). These two configurations have different luminous flux values due to the disparity in scattering properties in white LEDs. However, the researched results showed that FDRP structure is more lucrative than the CDRP structure when it comes to the luminous flux effectiveness. To support the aforementioned idea, this article also presents the influence of the distance between two phosphor layers (d1) and the distance between the phosphor layer with the LED surface (d2) on the optical properties of the FDRP structure. Specifically, the scattering ability and absorption properties of the remote phosphor layer will vary sharply if d1 and d2 are adjusted into different values, which produces an immense impact on the chromatic homogeneity and illumination capability of WLEDs. Therefore, in order to stabilize the correlated color temperature (CCT) of WLEDs at 8500 K when there is a modification on d1 and d2, the concentration of YAG:Ce3+ phosphor also needs to be varied. Accordingly, the scattering process and absorption phenomenon in the remote phosphor layer will bottom out when d1 = d2 = 0,  leading to the worst color quality and luminous flux. The effect of the spectra generated as these distances are adjusted is obvious evidence for this point. In other words, the larger the d1 and d2, the larger the scattering surface, and thus the blending of blue and yellow light rays will become more homogeneous, yielding the smallest white light deflection and the lowest luminous flux at the same time. The paper's results indicated that the luminous flux will reach a peak at 1020 lm if d1 = 0.08 mm or d2 = 0.63 mm and the chromatic deflection will hit the lowest point as d1 = 0.64 mm or d2 = 1.35 mm. In the end, manufacturers can make their choice for the production of higher-standard WLEDs based on the general knowledge and helpful information that the article has provided and analyzed

Improving luminous flux and color homogeneity of dual-layer phosphor sctructure

In order to clarify the main purpose of the study, we put a green phosphor layer SrBaSiO4:Eu2+ on the yellow phosphorus layer YAG:Ce3+ through using only one WLEDs structure in different color temperatures like 5600 K, 6600 K, 7700K. Then, we find the suitable SrBaSiO4:Eu2+ concentration in order that the luminous flux could get the highest value. The results show that SrBaSiO4:Eu2+ brings great benefits to increase not only optical gain but also color uniformity. Specifically, the greater the SrBaSiO4:Eu2+ concentration, the greater the output of WLEDs because of the development of green light component in WLEDs. However, only if the SrBaSiO4:Eu2+ concentration exceeds the level, a slight decrease in color rendering index (CRI) can occur, which based on Monte Carlo simulation. In addition, the results of this paper have contributed significantly to the creation of higher-powered WLEDs

Improvement of Color Quality and Luminous Flux of WLEDs with Dual-Layer Remote Phosphor Configurations

In comparison with the conformal phosphor or in-cup phosphor structure, remote phosphor structure has a superior luminous flux whereas its color quality is inferior to the others’. Due to this drawback, it is essential to conduct experiments to find the solution for the improvement of the color quality of WLEDs using remote phosphor structure. In this study, a dual-layer remote phosphor structure that is capable of enhancing the Color Rendering Index (CRI) and Color Quality Scale (CQS) for WLEDs was proposed. Three kinds of WLEDs with the similar structures but different color temperatures varying at 5600 K, 7000 K, and 8500 K are used in this article. The mission of this paper is to place a yellow-green emitting SrBaSiO4:Eu2+ phosphor layer or a red-emitting SrwFxByOz:Eu2+,Sm2+ phosphor layer on the YAG:Ce3+ phosphor layer and then select the most appropriate value of SrwFxByOz:Eu2+,Sm2+ concentration to get the greatest color quality. Experimental results were exactly as expected since SrwFxByOz:Eu2+,Sm2+ really succeeded in increasing CRI and CQS. Specifically, the larger the SrwFxByOz:Eu2+,Sm2+ concentration, the higher the CRI and CQS, resulting from the increase of the red light component in WLEDs. Meanwhile, the quality degree of luminous flux depends tightly on the SrBaSiO4:Eu2+ phosphor layer. However, if the SrwFxByOz:Eu2+,Sm2+ and SrBaSiO4:Eu2+ concentration exceeds, the luminous flux and color quality will have a tendency to drop off thanks to the theory of Mie scattering and the Lambert-Beer law. The result of this paper is a valuable reference in the production of high-quality WLEDs

SEASONAL VARIATION OF PHYTOPLANKTON FUNCTIONAL GROUPS IN TUYEN LAM RESERVOIR, CENTRAL HIGHLANDS, VIETNAM

Seasonal changes in freshwater phytoplankton assemblages at Tuyen Lam Reservoir in the Central Highlands of Vietnam were classified into 23 functional groups based on physiological, morphological, and ecological characteristics. A total of 168 species were recorded during 10 surveys from 2015 to 2019 at 7 sampling sites, with Chlorophyta dominating in number of species. Phytoplankton abundance varied from 0.18×105 to 21.2×105 cells/L during the study period, mainly due to cyanobacteria. Seven of the 23 functional groups were considered to be dominant (relative density > 5%).  The dominant functional groups were groups M and G in the dry season and groups M, G, P, and E in the rainy season. Group M (Microcystis aeruginosa) was the most common in both seasons, while group P (Closterium, Staurastrum, Aulacoseira), group E (Dinobryon, Synura), and group G (Sphaerocystis, Eudorina) were more common in the rainy season. The Shannon diversity index (H¢) showed that phytoplankton communities were relatively diverse and that most of the study sites were lightly polluted. However, the ecological status has deteriorated at some locations due to the overgrowth of group M, leading to eutrophication in this reservoir. This study highlights the usefulness of functional groups in the study of seasonal changes in phytoplankton dynamics. Functional groups are applied for the first time at Tuyen Lam Reservoir and can be used to predict early-stage cyanobacterial blooms in future studies

Modeling the determinants of job satisfaction in Vietnam

The study focuses on a number of policy-relevant variables such as wage policy and training plans for workers, as well as absolute and relative wages, union membership, and job position. Possible differences in job satisfaction of workers in domestic versus Foreign Direct Investment (FDI) firms are examined. The research utilizes a unique employer-employee matched survey conducted by the North-South Institute (Canada) to investigate the determinants of job satisfaction, and survey data from the Center of Analysis and Forecasting, the Vietnam Academy of Social Sciences