Influence of Lead, an Environmental Pollutant on Metamorphosis of Rana utricularia (Amphibia: Ranidae)

The influence of lead, an environmental pollutant on metamorphosis of Rana utricularia, was examined in this study. Larvae of stage XI (Taylor and Kollros, 1946), beginning of the premetamorphic stage, were exposed to lead concentrations of 0.1 ppm, 0.5 ppm, 1.0 ppm and 1.5 ppm for 106 days. The untreated larvae served as controls. Larvae were observed from early limb bud stage, stage X, through the protrusion of the forelimbs, stage XX. Neither the sequence of developmental events nor the gross external and internal morphology was altered by lead. However, lead prolonged the time of metamorphosis by delaying the completion of each successive prometamorphic stage. The extent of delay was concentration dependent. The thyroid gland of the experimental larvae underwent alterations which were also concentration dependent. The size of the gland and the size of the follicle were reduced. Vacuolation occurred in the colloid of both 0.5 ppm and 1.5 ppm lead treated larvae

A CES APPROACH TO THE MEASUREMENT OF INDUCED FACTOR AUGMENTATION: A TEST FOR JAPAN

International Development,

INDUCED INNOVATION: A CES-TYPE META-PRODUCTION FUNCTION

Research and Development/Tech Change/Emerging Technologies,

Do Corporate Global Environmental Standards in Emerging Markets Create Or Destroy Market Value

Arguments can be made on both sides of the question of whether a stringent, global corporate environmental standard represents a competitive asset or liability for multinational enterprises (MNEs) investing in emerging and developing markets. This paper seeks to answer this question by analyzing the global environmental standards of a large sample of US-based MNEs in relation to their market performance. We find that firms adopting a single, stringent global environmental standard have higher market values, as measured by Tobin's q, than firms defaulting to less stringent, or poorly enforced host country standards. Thus, developing countries that use lax environmental regulations to attract foreign direct investment end up attracting poorer quality, and perhaps, less competitive firms. Our results also suggest that externalities are incorporated to a significant extent in firm valuation. We discuss plausible reasons for this observation.http://deepblue.lib.umich.edu/bitstream/2027.42/39644/3/wp259.pd

A Comparison of Visual Modeling Notations for Web Services Choreography

The Web Services Choreography Description Language (WS-CDL) is an XML-based language for specifying business protocols for \emph{web services enabled} collaborative processes. The use of visual notations in modeling web services choreography has so far been done in an ad hoc fashion as seen in the literature. This paper presents a choreography example in four different visual modeling notations and compares them with regard to the semantics of WS-CDL. The results are useful for establishing a reliable visual approach to modeling web services choreography

Optimization of resource allocation for the downlink of multiuser MISO-OFDM systems

Proceedings of the IEEE International Conference on Telecommunications, 2010, p. 266-271In this paper, we investigate the optimization problem of resource allocation in downlink of multiuser MISO-OFDM system. Multiple users with different BER and minimum transmission rate requirements are considered. We propose a novel heuristic allocation algorithm (HAA) of radio resource, which minimizes the total transmit power of the base station while meeting individual users'QoS requirements. The proposed algorithm combines antenna selection, subcarrier, bit and power allocation together, pre-estimating number of subcarriers assigned to each user and number of bits loaded for each subcarrier to reduce search number, reducing about 8 dB average bit SNR comparing with fixed allocation algorithm (FAA), and acquiring asymptotic average bit SNR of optimal allocation algorithm (OAA) with much lower complexity. © 2009 IEEE.published_or_final_versio