The Effects of Surface Albedo and Initial Lignin Concentration on Photodegradation of Sorghum Bicolor Litter

Photodegradation has been recognized as a contributor to litter decomposition in a wide variety of ecosystems, however many of the mechanisms that drive it remain unknown. The primary focus of this study was to investigate the effect of surface albedo on the rate at which plant litter photodegrades. The first hypothesis that was tested was that surfaces with higher albedo will increase the rate of mass loss. The second hypothesis was that a wild type Sorghum bicolor with higher lignin concentration will degrade more rapidly than a double mutant variety. Three different artificial surface covers (aluminum foil, black paint, and white paint) were used to mimic the surface albedo of natural surfaces. Two varieties of Sorghum bicolor (wild type (WT) & double mutant (DM)) that differed in initial litter chemistry were placed on the surfaces and exposed to varying levels of solar radiation for 200-d. Mass loss, cell wall constituent (hemicellulose, cellulose and lignin) concentrations and bulk-soluble phenolic concentrations were examined every 50-d, for the duration of the experiment. In support of our first hypothesis, decomposition of the WT and DM litter was generally faster on the aluminum surfaces than on the black and white surfaces. Litter collected from the aluminum surfaces lost an average of 1.71% more mass than the black surfaces and an average of 3.08% more mass than the white surfaces. In contrast to our second hypothesis, the higher lignin, WT litter, photodegraded at a slower rate than did the lower lignin, DM litter. Following the 200-d collection, DM litter lost approximately 5% more mass, with WT losing an average of 47.5% of initial mass, and DM losing an average of 52.6% across all surface types

A Multifractality Measure of Stock Market Efficiency in Asean Region

This paper investigates the presence of multifractality property of the daily composite stock price index of the six countries in the Association of Southeast Asian Nation (ASEAN) region using the multifractal detrended fluctuation analysis (MFDFA). Covering the period from January 2, 2006 to June 28, 2013, the countries under study are the following: Indonesia, Malaysia, Philippines, Singapore, Thailand and Vietnam. If multifractality is present, then the traditional time series models of fractional Brownian motion and GARCH processes are inadequate to capture the stylized facts observed in financial time series which include long-range correlations and broad fat-tail distributions. The study also employs a sliding window MFDFA to obtain the dynamics of the local Hurst exponents which can be used as a measure of market efficiency. The findings suggest that the stock price indices of the six countries under study have the properties of multifractality. These suggest that the traditional time series models of fractional Brownian motion and GARCH processes are not appropriate and a call for a better model which incorporates multifractality and non-Gaussian distributions is made. Moreover, an efficiency ranking of stock markets of the six countries under study is provided. This result is important to guide investors seeking profit opportunity which is dependent upon market efficiency. It is also important to help policy makers decide to implement institutional reforms aimed at increasing market efficiency. Keywords: Efficiency, Financial Markets, Multifractality, Hurst Exponen

Transformational Leadership and Organizational Commitment of Selected Higher Education Institutions in Zamboanga Peninsula

This study aimed to determine the level of transformational leadership practices of Deans and organizational commitment of faculty/staff members in Higher Education Institutions in the Zamboanga Peninsula. The five dimensions of transformational leadership studied were idealized influence (attribute), idealized influence (behavior), intellectual stimulation, and inspirational motivation. The study also looked into the level of organizational commitment of the staff and the relationship with the transformational leadership practices of the middle manager. The respondents of the study consisted of 103 faculty/staff employed in the selected Higher Education Institutions in the Zamboanga Peninsula, Philippines. Descriptive analysis and Pearson Correlation Coefficient were the statistical tools used by the researcher. The SPSS was used to examine the gathered data. The Deans' transformative leadership has a comparable impact on continued behavior and normative commitment, suggesting that continued behavior and normative commitment are affected by leadership in a complex way. Therefore, by enhancing their transformational leadership style, deans can raise faculty/staff retention levels and normative commitment. Furthermore, it is advised that future researchers do a study with a similar focus but a broader reach in higher education institutions

Assessing the Employment Conditions and Patterns of Help-outs among Selected Agrarian Reform Cooperatives in the Banana Industry

Employment is one of the key concepts that support every country’s economic activity. Its significance and contribution affect key players in all sectors, as it is vital in production, distribution, and consumption of commodities. Among all the industries, agriculture takes the largest share when it comes to labor force participation. The agricultural sector of the Philippines is composed of informally employed workers who face various issues in hiring, contracts, worker pay, workloads, and etc. These informally employed workers include “help-outs” who work in the Agrarian Reform Cooperatives (ARCs) managed by the Agrarian Reform Beneficiaries (ARBs). Due to the nature of work, these workers engage in different working arrangements which determine their farm setting. Thus, this is an exploratory study conducted to assess the working conditions and patterns of help-outs employed in the selected ARCs, namely SFARBEMCO, AMS-MARBEMCO, and AMS-KARBEMCO, in Davao del Norte. A total of 103 help-outs were interviewed. Linear and logit regression were both employed to test significance of relationships. The results show that most of the help-outs in the ARCs are well-off. Significant factors that affect their probability of being well-off include gender, rating of happiness, employment category, cooperative, and relationship to their ARB. However, issues identified in the employment patterns include ambiguous employer -employee relationship, payment of working slots, precarious contracts, unreasonable pay, and lack of social security

Étude expérimentale de la dissolution d'un mélange TCE+PCE dans un milieu poreux hétérogène

Le contexte général de notre étude concerne le développement de panaches de pollutions provoqués par la dissolution de solvants hydrocarbonés dans des nappes aquifères. De nombreuses études, tant expérimentales que numériques et théoriques, traitent de la dissolution de polluants organiques, mono constituants, dans des milieux poreux homogènes. Peu d’études sont consacrées au cas multi constituant. L’objectif de notre étude, expérimentale dans un premier temps, est de considérer un mélange de deux constituants hydrocarbonés dans des milieux poreux homogènes et hétérogènes. Les deux polluants considérés sont le TCE et le PCE, les milieux poreux homogènes sont des grès et des sables, le milieu poreux hétérogène est constitué de couches de sables et de grès alternées dans le sens orthogonal à l’écoulement. Après la mise en place initiale du polluant par drainage, on injecte en continu de l’eau pure en mesurant la concentration en polluant dans les effluents par chromatographie en phase gazeuse. Les résultats ont mis en évidence la dissolution sélective des 2 polluants. On constate, en début d’expérience, une phase d’équilibre locale qui est rapidement suivie d’une phase de non-équilibre local qui dure jusqu’à la fin de la dissolution des polluants. La comparaison des résultats obtenus avec des milieux hétérogènes et des résultats obtenus avec des milieux homogènes met clairement en évidence l’effet des hétérogénéités sur le processus de la dissolution