Taxing Emissions: A Theoretical Note

This report contains a short theoretical proof for the non-optima lity of a uniform emission tax. A method recently suggested for finding the optimal level of a uniform tax is criticized. An alternative tax system that could be either uniform or non-uniform that is gradually increasing over time is suggested instead. The paper is aimed at stimulating discussions on theoretical and empirical grounds on the feasibility and efficiency of the suggested tax.     

Seasonal ecology of hydrocarbon-utilizing microbes in the surface Waters of a river

Seasonal changes in the microbial communities of the New Calabar Riverwater have been investigated. Analyses of the BOD, pH, salinity, oil and grease levels of effluents of industries sited along the river were also conducted. High hydrocarbon-utilizing microbial populations were found. The percentage of hydrocarbon-utilizing heterotrophic bacteria ranged between 0–98% and 0–68% in the rainy and dry months, respectively. Counts of hydrocarbon-utilizing actinomycetes in the rainy months ranged between 0–95% and 2–55% in the dry months. The hydrocarbon-utilizing yeast population ranged between 1–95% and 2–85% for the rainy and dry months, respectively. Rainy month values for hydrocarbon-utilizing mould population ranged from 0–17% while dry month values ranged from 0–47%. The hydrocarbon-utilizing cyanobacterial population ranged between 0–95% and 0–33% in the rainy and dry months, respectively. Our results suggest that the heterotrophic bacterial and cyanobacterial populations are higher in the rainy months than in the dry months. However, the hydrocarbon-utilizing yeast, mould and actinomycete populations did not show seasonal variation.     

FUTURE SOURCES OF COOLING WATER FOR POWER PLANTS IN ARID REGIONS1

ABSTRACT: Electric generation facility water requirement will increase substantially in the future in the Western United States because new power plants are to be constructed at inland sites rather than on the coast. At the inland locations, power plants will have to compete with agriculture and public users for fresh water supplies, and will be constrained by environmental legislation to dispose of cooling waste water in lined evaporation ponds. The various options for power plant cooling are analyzed in respect to cost, water consumption, and environmental hazard, and also in respect to their compatibility with existing state and federal regulations. Several proposals for balancing the water requirements of various users in water-scarce areas are reviewed and criticized.     

Ecological and biological phenomena influencing coral-species composition on the reef tables at Eilat (Gulf of Aqaba,Red Sea)

Observations performed on coral colonies damaged during a very low tide on the shallow-water reef tables at Eilat (Red Sea), showed that most colonies are able to regenerate if parts of the living tissue remain intact on the skeletons. Brain-like corals, such asFavia favus andPlatygyra lamellina, were found to be more resistant to dessication than the delicate bush-like forms. It was also observed that the exposed skeletons of corals were immediately covered by a successive group of algae with a rich invertebrate epifauna among them. It is postulated that unpredicted extreme low water, occurring once in several years, could be the factor that prevents crowding on the reef tables, thus keeping high the level of coralspecies diversity.Supported, in part, by a grant from the Smithsonian Institution, USA. SFC-70074.This paper was presented at the Intecol Symposium held in Dubrovnik in March, 1972.     

Amniocentesis rate and the detection of down syndrome and other chromosomal anomalies in Israel

We investigated the contribution of different screening criteria to the prenatal detection of Down syndrome (DS) as well as other chromosomal anomalies in the Jewish population in Israel during 1990 and 1992. There was a significant decrease (P<0·03) in the incidence of DS live-births during 1992 (40:78 442) compared with 1990 (69:73 751) which paralleled a marked increase in total prenatal testing and in DS cases detected prenatally. Private laboratories, which perform amniocenteses mostly for women with a low risk of DS and without genetic counselling, had a significantly lower detection rate (1:917) compared with that of the genetic institutes, which following genetic counselling test both women ≥ 37 years of age (1:91) and women younger than 37 years (1:113). The detection of chromosomal anomalies other than DS was less affected by the reason for amniocentesis. Amniocentesis indicated by maternal serum marker screening of women younger than 37 years identified a greater number of chromosomal anomalies other than DS than amniocentesis based on age (≥37 years) alone (111:9604 versus 94:9810; P<0·06). Prenatal detection of DS is most effective when the indication for amniocentesis follows genetic counselling. The increasing use of maternal serum marker screening leads to a significant improvement in the positive detection rate of chromosomal anomalies other than DS in young women.     

Rodlet Cells in the Head and Trunk Kidney of the Domestic Carp (Cyprinus carpio): Enigmatic Gland Cells or Coccidian Parasites?

 Rodlet cells have been found in the head and trunk kidneys of the common carp (Cyprinus carpio L.). From an experimental sample of 50 carps of various ages, we detected these cells in only seven fishes, contradicting the hypothesis that they constitute a normal component of the fish epithelia. The rodlet cells have a typical structure: 12–16 μm in diameter, with a basal nucleus various in form, and an encasing layer of fibrillar structure. The cells contain rodlets, composed of elongated, opaque sacs featuring dark rods in the center, which strongly elongate in ripening cells. Remarkable pseudopodia-like extensions from the apical parts of the rodlet cells penetrate into the delicate blood vessels and sinusoids of the organs. The encasing layer at the cell apex then opens to release the rodlets into the bloodstream. No junctions were found between the rodlet cells and neighboring cells. It is suggested that these cells comprise some kind of "symbiosis" between leukocyte, possible granulocyte cells, and the parasitic rodlets. The cells serve the rodlets as an incubation chamber, as well as a means of transportation into the bloodstream after ripening. Received: 29 December 1998 / Accepted in revised form: 3 March 1999     

Are perseverance and self‐efficacy costless? Assessing entrepreneurs' regretful thinking

New business formation is a formidable and daunting task, which may require personal perseverance and self‐efficacy. If this is indeed the case, will entrepreneurs and non‐entrepreneurs differ on such attributes? Also, if high levels of perseverance and self‐efficacy help entrepreneurs to overcome setbacks, snags, and obstacles, do these positive attributes co‐occur with significant personal costs, such as the tendency to experience regretful thinking? This study uses a random sample of 217 patent inventors in the medical industry (surgery devices) to address these questions. Results indicate that entrepreneurs score significantly higher on self‐efficacy and on two distinct aspects of perseverance—perceived control over adversity and perceived responsibility regarding outcome of adversity—than did non‐entrepreneurs. Also, although entrepreneurs report the same number of regrets, their regrets are stronger and are qualitatively different from those reported by non‐entrepreneurs. These findings suggest that perseverance and self‐efficacy do indeed co‐occur with regretful thinking. Finally, post hoc analysis reveals that the higher the overall perseverance scores of patent inventors, the higher their annual earnings. We conclude by examining the implications for theory, researcher, and practice. Copyright © 2005 John Wiley & Sons, Ltd.     

Rural market imperfections and the role of institutions in collective action to improve markets for the poor

Many countries in sub‐Saharan Africa have liberalized markets to improve efficiency and enhance market linkages for smallholder farmers. The expected positive response by the private sector in areas with limited market infrastructure has however been very limited. The functioning of markets is constrained by high transaction costs and coordination problems along the production‐to‐consumption value chain. New kinds of institutional arrangements are needed to reduce these costs and fill the vacuum left when governments withdrew from markets in the era of structural adjustments. One of these institutional innovations has been the strengthening of producer organizations and formation of collective marketing groups as instruments to remedy pervasive market failures in rural economies. The analysis presented here with a case study from eastern Kenya has shown that marketing groups pay 20–25% higher prices than other buyers to farmers while participation was also positively correlated with adoption of improved dryland legume varieties, crops not targeted by the formal extension system. However the effectiveness of marketing groups is undermined by external shocks and structural constraints that limit the volume of trade and access to capital and information, and require investments in complementary institutions and coordination mechanisms to exploit scale economies. Successful groups have shown high levels of collective action in the form of increased participatory decision making, member contributions and initial start‐up capital. Failure to pay on delivery, resulting from lack of capital credit, is a major constraint that stifles competitiveness of marketing groups relative to other buyers. These findings call for interventions that improve governance and participation; mechanisms for improving access to operating capital; and effective strategies for risk management and enhancing the business skills of farmer marketing groups.     

Polymorphism in gigantobacterial symbionts in the guts of surgeonfish (Acanthuridae: Teleostei)

The morphology and partial cytology of a group of bacteria-related organisms from the guts of surgeonfish are described. These gigantobacteria symbionts are encountered in the guts of various species of this fish family throughout the Indo-Pacific region and the Red Sea. They have been tentatively grouped and placed in a “family”, Epulopiscidae, according to the first species described, Epulopiscium fishelsoni Montgomery and Pollak, 1988. In addition to a morphological comparison between the various forms from different species of surgeonfish, suggestions are presented with regard to their possible morphological diversification during evolutionary and host-species specificity. Received: 10 June 1998 / Accepted: 29 October 1998