Dance precision of <Emphasis Type="Italic">Apis florea</Emphasis>—clues to the evolution of the honeybee dance language?

All honeybee species make use of the waggle dance to communicate the direction and distance to both food sources and potential new nest sites. When foraging, all species face an identical problem: conveying information about profitable floral patches. However, profound differences in nesting biology (some nest in cavities while others nest in the open, often on a branch or a cliff face) may mean that species have different requirements when dancing to advertise new nest sites. In cavity nesting species, nest sites are a precise location in the landscape: usually a small opening leading to a cavity in a hollow tree. Dances for cavities therefore need to be as precise as possible. In contrast, when the potential nest site comprises a tree or perhaps seven a patch of trees, precision is less necessary. Similarly, when a food patch is advertised, dances need not be very precise, as floral patches are often large, unless they are so far away that recruits need more precise information to be able to locate them. In this paper, we study the dance precision of the open-nesting red dwarf bee Apis florea. By comparing the precision of dances for food sources and nest sites, we show that A. florea workers dance with the same imprecision irrespective of context. This is in sharp contrast with the cavity-nesting Apis mellifera that increases the precision of its dance when advertising a potential new home. We suggest that our results are in accordance with the hypothesis that the honeybees’ dance communication initially evolved to convey information about new nest sites and was only later adapted for the context of foraging.     

A Multi‐Scale Analysis of Single‐Family Residential Water Use in the Phoenix Metropolitan Area

Studies that evaluate determinants of residential water demand typically use data from a single spatial scale. Although household‐scale data are preferred, especially when econometric models are used, researchers may be limited to aggregate data. There is little, if any, empirical analysis to assess whether spatial scale may lead to ecological fallacy problems in residential water use research. Using linear mixed‐effects models, we compare the results for the relationship of single‐family water use with its determinants using data from the household and census tract scales in the city of Phoenix. Model results between the household and census tract scale are similar suggesting the ecological fallacy may not be significant. Common significant determinants on these two spatial scales include household size, household income, house age, pool size, irrigable lot size, precipitation, and temperature. We also use city/town scale data from the Phoenix metropolitan area to parameterize the linear mixed‐effects model. The difference in the parameter estimates of those common variables compared to the first two scales indicates there is spatial heterogeneity in the relationship between single‐family water use and its determinants among cities and towns. The negative relationship between single‐family house density and residential water use suggests that residential water consumption could be reduced through coordination of land use planning and water demand management.     

Enhanced sludge solubilization by microbubble ozonation

A microbubble ozonation process for enhancing sludge solubilization was proposed and its performance was evaluated in comparison to a conventional ozone bubble contactor. Microbubbles are defined as bubbles with diameters less than several tens of micrometers. Previous studies have demonstrated that microbubbles could accelerate the formation of hydroxyl radicals and hence improve the ozonation of dyestuff wastewater. The results of this study showed that microbubble ozonation was effective in increasing ozone utilization and improving sludge solubilization. For a contact time of 80 min, an ozone utilization efficiency of more than 99% was obtained using the microbubble system, while it gradually decreased from 94% to 72% for the bubble contactor. The rate of microbial inactivation was obviously faster in the microbubble system. At an ozone dose of 0.02 g O₃ g⁻¹ TSS, about 80% of microorganisms were inactivated in the microbubble system, compared with about 50% inactivation for the bubble contactor. Compared to the bubble contactor, more than two times of COD and total nitrogen, and eight times of total phosphorus content were released from the sludge into the supernatant by using the microbubble system at the same ozone dosage. The application of microbubble technology in ozonation processes may provide an effective and low cost approach for sludge reduction.     

Assessing Landscape Condition Relative to Water Resources in the Western United States: A Strategic Approach

The Environmental Monitoring and Assessment Program (EMAP) is proposing an ambitious agenda to assess the status of streams and estuaries in a 12-State area of the western United States by the end of 2003. Additionally, EMAP is proposing to access landscape conditions as they relate to stream and estuary conditions across the west. The goal of this landscape project is to develop a landscape model that can be used to identify the relative risks of streams and estuaries to potential declines due to watershed-scale, landscape conditions across the west. To do so, requires an understanding of quantitative relationships between landscape composition and pattern metrics and parameters of stream and estuary conditions. This paper describes a strategic approach for evaluating the degree to which landscape composition and pattern influence stream and estuary condition, and the development and implementation of a spatially-distributed, landscape analysis approach.     

How do trade and economic growth impact environmental degradation? New evidence and policy implications from the ARDL approach

Environmental Science and Pollution Research - Due to various environmental degradation and natural resource depletion around the world, researchers’ and policymakers’ attention has...     

Environment,development and sustainability of local practices in the sacred groves and shrines in Bongo District: a bio-cultural study for environmental management in Ghana

The eminent crisis threatening biological and resource diversity is a global adversity. Global resource diversities are constantly disappearing and deteriorating at quite an alarming proportion, provoking renewed thinking regarding the effectiveness of existing environmental management approaches and practices. For the past four decades, several epochs of environmental management policies and practices disregarded the cultural imperative for safeguarding efficient environmental management outcomes, particularly at the community level. Even in the rouse of this reality, issues of spirituality and how it binds local community people to their natural environment appear to be given only a window dressing attention through the recognition of sacred natural sites. Eight sacred groves and shrines in the Bongo District were investigated based on an endogenous development framework. The data were collected using focus group discussions with stakeholders at the local and district levels and individual interviews with key local natural resource managers from four selected communities. The study revealed that the way indigenous people construct the worldviews and interactions with nature using ancestors and other spirit mediums can safeguard the environment against long periods of human interference and destruction. It also demonstrates that in certain places traditional institutions are becoming malleable and open to the use of external knowledge and resources in order to sustain places of sacred significance. It concludes that cultural imperative and the issues of spirituality are critical for the sustainable management of environmental resources. The study recommends revisiting local practice and cultural values that promote good environmental management practices within the local communities.     

Signaltransduktion in Sehzellen

2+   concentration. This review describes our present knowledge about the signal transduction and its fine tuning by a complex network of Ca²⁺-mediated processes in vertebrate photoreceptors.      

Estimation of selected physicochemical properties for methylated naphthalene compounds

Liquid aqueous solubility (S(w,L)), octanol/water partition coefficients (K(ow)), liquid vapor pressure (P(v,L)), and Henry's law constants (H(c)) were estimated for 20 methylated naphthalenes ranging from monomethyl to tetramethylnaphthalenes. Chromatographic methods were used for the estimation. Chromatographic retention measurements were conducted for 11 reference compounds and regressions were fit between the retention indices and the physicochemical properties. HPLC octadecylsilyl column with acetonitrile/water eluent was used for the estimation of S(w,L) and K(ow). Two GC columns, HP5-MS and a more hydrophobic HP-1, were tested for the estimation of P(v,L). Measured retention indices for the methylated naphthalenes were entered to the regression equations to calculate the physicochemical properties for these compounds. Literature values, where available, were used to validate the calculated values. The method accurately estimated the physicochemical properties. Estimated S(w,L) and P(v,L) decreased with the number of methyl groups. K(ow) increased with the number of methyl groups. There was no obvious relation between H(c) and the number of methyl groups. Log S(w,L) ranged from 0.885 for 1,2,5,6-tetramethylnaphthalene to 2.269 for 1-methylnaphthalene (mmol/m(3)). Log K(ow) varied from 3.89 for 1-methylnaphthalene to 4.95 for 1,2,5,6-tetramethylnaphthalene. Log P(v,L) ranged from -0.983 for 1,2,5,6-tetramethylnaphthalene to 0.789 for 2-methylnaphthalene (Pa). Log H(c) varied from 1.03 for 1,4,5-trimethylnaphthalene to 1.73 for 2,6-dimethylnaphthalene (Pa m(3)/mol). There were no apparent effects of GC column hydrophobicity on the accuracy of the results. Estimation of S(w,L) and K(ow) based on GC retention indices was not as accurate as with HPLC. Comparison of the estimated values with values predicted by EPIWIN indicated that EPIWIN is useful in giving order-of-magnitude prediction of physicochemical properties.