Transfer of symbiotic luminous bacteria from parental Leiognathus nuchalis to their offspring

Juveniles of Leiognathus nuchalis were raised from fertilized eggs for up to 60 d and examined for luminescence activity. Almost all juveniles raised separately from adults failed to produce detectable light. In contrast, a significant percentage (33 to 100%) of the juveniles became luminescent in less than 48 h when they were either kept with adults or inoculated with a homogenate of the adult light organs. The luminescence tended to increase with time after the treatments. These findings suggest that: (1) most of L. nuchalis offspring typically hatch and develop apo-symbiotically and (2) at least 45 d after hatching, juveniles can be infected with symbiotic luminous bacteria from the light organ of adult fish, and thereby gain the ability to produce light. Received: 16 February 1999 / Accepted: 21 September 1999     

Resource utilization for decorating in three intertidal majid crabs (Brachyura: Majidae)

 For three spider crabs (Tiarinia cornigera, Micippaplatipes and Pugettia quadridens quadridens), patterns of algal utilization for decorating were compared with the dynamics of algae on an intertidal rocky shore reef where the crabs co-occurred. T. cornigera and P. quadridens quadridens were most abundant from autumn to spring when the dominant algae (Boodleacoacta, Sargassum hemiphyllum, S. thunbergii and Corallina pilulifera) occurred in high coverage, while M. platipes was most abundant from spring to autumn. Monthly change of algae used for decorating was not correlated with algae growing in the crab habitat for T. cornigera, but for M. platipes, it was positively correlated for two algal species, and for P. quadridens quadridens, negatively correlated for one algal species. Each species of the spider crabs used some algal species preferentially for decoration. Decorating preference experiments conducted in the laboratory showed that M. platipes and P. quadridens quadridens exhibited similar preference to their algal utilization in the field, whereas for T. cornigera, algal preference in the experiment differed from utilization in the field. Comparisons between materials used for decoration and gut contents revealed that T. cornigera and M. platipes used algal species differently for decorating and feeding, while P. quadridens quadridens used the same algal species for both decorating and feeding. Different tactics for camouflage are discussed in terms of algal utilizations by the three majid species. Received: 25 September 1999 / Accepted: 22 June 2000     

Situational Waste in Landscape Watering: Residential and Business Water Use in an Urban Utah Community1

Abstract: Landscape water conservation is an important issue for municipalities throughout the Western United States, and especially in Utah as rapid growth strains existing water supplies. We conducted interdisciplinary research in Layton, Utah, that aimed at understanding patterns of landscape water use among households and businesses. The research project involved three basic tasks. First, a landscape “water budget” was developed by producing a calibrated and classified mosaic of landscape type and area from airborne multispectral digital imagery, integrating this information with Layton City parcel boundary data to determine landscape vegetated areas per lot, and estimating irrigation needs derived from reference evapotranspiration (ETo) obtained using weather data for the Salt Lake City metropolitan region. Second, utilizing Layton water billing data, water use for each household and business was identified and categorized as “conserving,”“acceptable” or “wasteful” by determining how much the water applied varied from actual landscape plant need. Third, surveys were administered to a random stratified sample of households and businesses in the study area to investigate various factors that were hypothesized to be predictive of wasteful watering practices. This paper primarily focuses on analysis of the household and business survey data, which explores factors affecting urban landscape water use from a human behavioral perspective. We found that the most significant factors predicting actual water use were the type of irrigation system and whether the location was a household or business. Attitudinal and motivational characteristics were not consistently associated with water use. We found that wasteful watering is the result of many factors embedded in the complex context of urban landscapes. This implies that water conservation programs should identify potential wasteful users through analyses of water billing data and direct water conservation measures at these users by focusing on site‐specific evaluations and recommendations. Water audits or water checks are one such tool that some communities have employed to help people understand and assess the quantity of water needed by and applied to their landscapes. This approach provides an opportunity to evaluate situational constraints at particular locations and design appropriate strategies for reducing water waste.     

Evaluating household waste treatment systems with specific examination of collection and transportation processes

To form a sustainable recycling society, control industrial waste, and reutilize resources from waste to the greatest extent possible, we evaluated the waste collection system in terms of CO₂ emissions, the energy consumed, the amount recycled, the final disposal amount, and cost, particularly addressing the collection and transportation processes of domestic waste and using LCA evaluation for multiple policies. The results showed that enforcement of a combination of five optimal policies (as assessed in terms of their evaluation indexes), i.e., the use of clean energy gas-powered vehicles, the station method, collection of waste segregated into 11 categories, collective collection, and simple pay-as-you-go charges, might cultivate residents’ sense of responsibility in terms of controlling waste discharge.     

Soil heterogeneity effects on acid flushing of lead-contaminated soil

A compact model for evaluation of acid flushing of heavy-metal-contaminated soil in a small-scale on-site treatment plant is proposed. The model assumes that the soil was re-packed in a container after excavation resulting in a soil structure with heterogeneous and random physical and chemical properties. To evaluate the effects of heterogeneity on the efficiency of contaminant removal by acid flushing, a numerical analysis of lead transport in the heterogeneous soil medium was performed. The model examines cation exchange and surface complexation reactions involving three cations (Ca, Pb, and H) and one anion (Cl) in both dissolved and exchangeable forms, two Pb surface complexes (SOPbCl and SOPbOH), and one Cl surface complex (SOH₂Cl). The transport of these species during flushing with acid in a synthetically generated two-dimensional heterogeneous soil was simulated in the model. Results indicated that the flushing fluid preferentially followed pathways with large permeability. The heterogeneous cation exchange capacity (CEC) distribution and surface complexation sites had a significant effect on the transport of dissolved species. Because the CEC was set to a relatively low value, Pb was adsorbed mainly as surface complexes (SOPbCl and SOPbOH). Simulation results suggest that blocks of low hydraulic conductivity located in the upper part of the model domain greatly impede solute transport. Ponding conditions did not significantly affect the efficiency of decontamination. The model and its results are useful in the design of small-scale treatment plants for acid flushing.     

Function of the major cheliped in male–male competition in the hermit crab <Emphasis Type="Italic">Pagurus nigrofascia</Emphasis>

Functions of the major cheliped in pagurid hermit crabs have been studied in fights for shells. The major cheliped often shows sexual size dimorphism, suggesting that sexual selection favors the development of the male major cheliped. The function of the major cheliped in male–male competition was examined in Pagurus nigrofascia collected from April to June 2009 on the intertidal rocky shore in southern Hokkaido, Japan (41°N, 140°E). Sexual size dimorphism of the major cheliped was observed, and precopulatory guarding males had larger major chelipeds than solitary ones. Guarding males used the major cheliped to deter intruders during competitive interactions. Males without a major cheliped were disadvantaged even if they were larger than opponents and had ownership. Cheliped size affected the outcomes of contests between similar sized males. This suggests that the male major cheliped in P. nigrofascia protects mates from competitors and, consequently, enhances male mating success. Sexual selection may favor the development of the major cheliped in male pagurids.     

Characterizing and Contextualizing the Water Challenges of Megacities

We characterize and compare water challenges confronting the 28 megacities of the world in 2014. Relying on existing literature and diverse primary data sources, we present a unique portrait at a global scale of the water implications of the rapid growth in megacities. We find that differentiating and analyzing the complexity of megacities' water problems based on geographic contexts, historical development trajectories, urban population growth rates, and forms of urban expansion helps explain the nature of the various water management problems they confront. Two governance features also shed light on megacity water challenges: fragmentation resulting from forms of megacity urban expansion; and, urban dualism resulting from contradictions between historical and cultural legacies and the rise of global engineering and technological norms for water management. The increasing vulnerability of megacities to climate change poses risks as well as opportunities for a more collective response to address this global phenomenon. Our analysis raises important questions and offers guidance about the future trajectories of many more large cities around the world that are on their way to becoming megacities.     

Synchronized development of gonad and bioluminescent light organ in a highly sexually dimorphic leiognathid fish, Photoplagios rivulatus

In order to investigate the possible coupling between sexual maturation and the light organ system (LOS) development in leiognathid fish, we determined the seasonal changes in the gonad maturation and the light organ enlargement in Photoplagios rivulatus, one of the leiognathid species possessing highly sexually dimorphic LOS. The fish specimens collected from March 2001 to August 2002 were assessed for standard length (SL), body weight (BW), sex, gonad weight (GW) and the light organ weight (LW). Gonadosomatic index (GSI = 10²GW/BW) and percent weight of the light organ to body weight (PLW = 10² LW/BW) were used to demonstrate the extent of development of gonad and the LOS, respectively. Mean GSIs in both male and female increased in June through August. The mean PLW in males showed a similar trend to that of the GSI, while PLW in females showed no clear seasonal trends. A significant positive correlation was found between the GSI and the PLW in males but not in females. The onset of sexual maturity in males (55 mm SL) coincided with that of the light organ enlargement. These results strongly support the functional coupling between reproduction and bioluminescence in this species of leiognathid. From an evolutionary perspective, sexual dimorphism in the LOS is likely to have evolved through sexual selection for reproductive success in leiognathid fishes.     

Carcinogenic tryptophan pyrolysis products in cigarette smoke condensate and cigarette smoke-polluted indoor air

The carcinogenic tryptophan pyrolysis products, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido-[4,3-b]indole (Trp-P-2), have been measured in condensate of cigarette mainstream smoke by high-performance liquid chromatography. These carcinogens have been detected in indoor air as well as in the air of the outdoor environment. Levels of these carcinogens in indoor air were much higher than those in outdoor air. The source of these carcinogens in indoor air was determined to be cigarette smoke by the application of smoking machine studies. Concentrations of these carcinogens in indoor air increased markedly with an increase in cigarettes smoked. The results in this investigation suggest that cigarette smoking is a source of carcinogenic tryptophan pyrolysis products in the indoor environment. Our data also suggest that smokers are persistently exposed to the carcinogenic heterocyclic amines together with potent carcinogens such as polynuclear aromatic hydrocarbons and N-nitroso compounds.