Combined use of pheromone trails and visual landmarks by the common garden ant Lasius niger

This study investigated the relative importance of pheromone trails and visual landmarks on the ability of Lasius niger foragers to relocate a previously used food source. Colonies formed foraging trails to a 1-M sucrose feeder. Sections of this trail were then presented back to the same colony after variable time intervals. Individual outgoing foragers were observed to determine if they walked for 15 cm in the direction of the feeder or not. On newly established pheromone trails formed by 500 ant passages, 77% of the foragers walked in the correct direction vs 31% for control foragers (no trail pheromone). Pheromone trails decayed to the control levels in 20–24 h. Trails formed with fewer ant passages (125 or 30) decayed quicker. The use of visual landmarks was investigated by using trails with outgoing foragers from the colony that established the trail, either in the same room or in a different room, with different visual landmarks, to that used during trail establishment. Approximately 20% more ants walked in the correct direction in the same room vs the different room. This difference decreased to around 10% 2 h after trail establishment, indicating that the ants in the different room were learning the new visual cues to navigate by. Our results show that visual landmarks and pheromone trails are approximately equally useful in initially guiding L. niger foragers to food locations and that these two information sources have a complementary function.     

Chemical characterization of fatty acids,alkanes, n-diols and alkyl esters produced by a mixed culture of Trichoderma koningii and Penicillium janthinellum grown aerobically on undecanoic acid,potatoe dextrose and their mixture

Little is known about the mixed fungal synthesis of high-value aliphatics derived from the metabolism of simple and complex carbon substrates. Trichoderma koningii and Penicillium janthinellum were fed with undecanoic acid (UDA), potatoe dextrose broth (PDB), and their mixture. Pyrolysis Field Ionization Mass Spectrometry (Py-FIMS) together with ¹H and ¹³C Nuclear Magnetic Resonance (NMR) characterized CHCl₃ soluble aliphatics in the fungal cell culture. Data from NMR and Py-FIMS analysis were complementary to each other. On average, the mixed fungal species produced mostly fatty acids (28% of total ion intensity, TII) > alkanes (2% of TII) > n-diols (2% of TII) > and alkyl esters (0.8% of TII) when fed with UDA, PDB or UDA+PDB. The cell culture accumulated aliphatics extracellularly, although most of the identified compounds accumulated intracellularly. The mixed fungal culture produced high-value chemicals from the metabolic conversion of simple and complex carbon substrates.     

Buy Me a River: Purchasing Water Rights to Restore River Flows in the Western USA

In recent decades, public and private environmental entities have been purchasing or leasing water rights across the Western United States (U.S.) in efforts to restore river flows and aquatic ecosystems. The need to pay for flow restoration arises from the fact that state governments did not begin to reserve water for instream purposes until the 1970s, long after water rights had become over‐appropriated and flows were substantially depleted in most rivers. As a consequence, flow depletion has become the leading cause of fish endangerment in the U.S., including the imperilment of two‐thirds of all native fish species in the Colorado River system. This paper takes stock of the progress made in buying water for the environment, specifically by reviewing and analyzing more than 50 transactions executed by public and private entities and the sources of funding underpinning these transactions. We conclude that nongovernmental actors — such as environmental organizations and state water trusts — are integral to regional efforts to restore river flows; these nongovernmental actors executed more than two‐thirds of the transactions we documented. However, we also conclude that the long‐term success of these nongovernmental actors depends upon the availability of sustained public funding that enables them to build capacity and engage in the large number of transactions needed to restore flows across each state.     

The effects of ethylene chlorohydrin on fatty acid synthesis 1 2 3

Abstract

Male chicks weighing 700 to 900 g. received an acute or eight doses IG of 60 or 40 mg/kg ethylene chlorohydrin (ECH) respectively and were sacrificed eighteen hours after the last dose. Mitochondrial elongation of fatty acids was decreased significantly while fatty acid synthetase activity was not significantly affected by ECH treatment. Cytochrome c oxidase activity in fresh whole liver homogenate was significantly higher in chicks subjected to acute exposure with ECH when compared to the controls. Upon freezing and thawing of homogenates, cytochrome c oxidase activity increased significantly in the control group but was unchanged in the ECH group which suggests that the mitochondrial membrane integrity is compromised by the ECH treatment. Serum and liver triglyceride levels were significantly elevated in both the single and multiple ECH dose groups. Liver to body weight ratios were significantly higher in both treatment groups when compared to their controls. Histological examination of the liver of ECH‐treated chicks showed cytoplasmic clearing of the cells but no vacuolization or centri‐lobular necrosis. Serum isocitrate dehydrogenase levels were significantly higher in the multiple treatment ECH group than in the control group.     

Observations of urban airborne particle number concentrations during rush-hour conditions: analysis of the number based size distributions and modal parameters

A summertime study of the number concentration and the size distribution of combustion derived nanometre sized particles (termed nanoparticles) from diesel and spark-ignition (SI) engine emissions were made under rush-hour and free-flow traffic conditions at an urban roadside location in Leeds, UK in July 2003. The measured total particle number concentrations (N(TOTAL)) were of the order 1.8 x 10(4) to 3.4 x 10(4) cm(-3), and tended to follow the diurnal traffic flow patterns. The N(TOTAL) was dominated by particles < or =100 nm in diameter which accounted for between 89-93% of the measured particle number. By use of a log-normal fitting procedure, the modal parameters of the number based particle size distribution of urban airborne particulates were derived from the roadside measurements. Four component modes were identified. Two nucleation modes were found, with a smaller, more minor, mode composed principally of sub-11 nm particles, believed to be derived from particles formed from the nucleation of gaseous species in the atmosphere. A second mode, much larger in terms of number, was composed of particles within the size range of 10-20 nm. This second mode was believed to be principally derived from the condensation of the unburned fuel and lube oil (the solvent organic fraction or SOF) as it cooled on leaving the engine exhaust. Third and fourth modes were noted within the size ranges of 28-65 nm and 100-160 nm, respectively. The third mode was believed to be representative of internally mixed Aitken mode particles composed of a soot/ash core with an adsorbed layer of readily volatilisable material. The fourth mode was believed to be composed of chemically aged, secondary particles. The larger nucleation and Aitken modes accounted for between 80-90% of the measured N(TOTAL), and the particles in these modes were believed to be derived from SI and diesel engine emissions. The overall size distribution, particularly in modes II-IV, was observed to be strongly related to the number of primary particle emissions, with larger count median diameters observed under conditions where low numbers of primary soot based particles were present.     

Lead in New York City community garden chicken eggs: influential factors and health implications

Raising chickens for eggs in urban areas is becoming increasingly common. Urban chickens may be exposed to lead, a common urban soil contaminant. We measured lead concentrations in chicken eggs from New York City (NYC) community gardens and collected information on factors that might affect those concentrations. Lead was detected between 10 and 167 μg/kg in 48 % of NYC eggs. Measures of lead in eggs from a henhouse were significantly associated (p < 0.005) with lead concentrations in soil. The association between soil and egg lead has been evaluated only once before, by a study of a rural region in Belgium. In our study, the apparent lead soil-to-egg transfer efficiency was considerably lower than that found in Belgium, suggesting that there may be important geographic differences in this transfer. We developed models that suggested that, for sites like ours, lead concentrations in >50 % of eggs from a henhouse would exceed store-bought egg concentrations (<7–13 μg/kg; 3 % above detection limit) at soil lead concentrations >120 mg/kg and that the concentration in one of six eggs from a henhouse would exceed a 100 μg/kg guidance value at soil lead concentrations >410 mg/kg. Our models also suggested that the availability of dietary calcium supplements was another influential factor that reduced egg lead concentrations. Estimates of health risk from consuming eggs with the lead concentrations we measured generally were not significant. However, soil lead concentrations in this study were <600 mg/kg, and considerably higher concentrations are not uncommon. Efforts to reduce lead transfer to chicken eggs and associated exposure are recommended for urban chicken keepers.     

Some bacteriological aspects of poultry litter used as feed supplement in rabbit diets

An investigation was carried out to determine the microbial load in poultry litter used as feed supplement in rabbit diets. Before heat treatment by deep stacking the poultry litter, samples of the litter were collected to assay for microbial load at the Microbiology Laboratory of the Rivers State University of Science and Technology, Port Harcourt, Nigeria. Results obtained showed that before heat-treating the poultry litter, Escherichia coli, Salmonella, Mycobacterium, Clostridium and Staphylococcus were isolated at 41, 37, 37, 41 and 42°C, respectively. The results obtained also indicate that no pathogen was isolated after heat treatment of between 40 and 55°C for 21 days. This study justifies the suitability of using poultry litter as a feed supplement.     

Deep stacking poultry litter as feed ingredient in livestock production

The compelling need to harness the potentials of the numerous agro-industrial by-products and the so-called “wastes” as part replacement for the more expensive conventional feed ingredients have been seriously expressed. This need has arisen mainly from the increasing demand and supply deficit of conventional feed resources with a concomitant sharp rise in their cost prices. The net effect of increased unit cost of the conventional feed resources is increased cost of the compounded rations, which by extension gives rise to increased cost of meat and animal products. It then becomes highly imperative that other sources for rapid livestock output to meet the growing human demands for animal protein foods are sourced. Such other sources should be cheap and nutritionally adequate for feeding animals with the aim of lowering the cost of producing meat. One of such measure is the recycling of poultry litter as part replacement for soya bean in livestock nutrition. Poultry litter is the by-product of poultry production, which should be managed in an environmentally friendly manner. As observed in this study, poultry litter contains 20% crude protein, 621.41 ME kcal kg^?1, and substantial amounts of minerals that could be exploited in feeding livestock. This study has explored the possibility of including poultry litter in diets in view of its contents.     

Is dew water potable? Chemical and biological analyses of dew water in Ajaccio (Corsica Island, France)

To determine to what extent dew water is potable without further treatment, a thorough set of chemical and biological analyses were performed on 10 samples of dew water collected on a large scale radiative collector (29.83 m2) in Ajaccio (Corsica Island, France), between 21 May 2002 and 5 Mar. 2003. Samples were collected following four protocols according to the dew volume amount and 48 parameters (ions, minerals, and bacteria) were analyzed and compared to French and European Union legislation and also World Health Organization (WHO) recommendations. Aluminum and Fe were the main pollutants whose concentrations were significantly larger than recommended. Their presence is due to local deposition of aerosols coming from the Sahara (a characteristic of the Mediterranean basin). A large number of biologically cultivable microorganisms were found, together with bacteria typical of fecal contamination. For dew water to be potable with respect to present legislation at the Ajaccio site, it should be disinfected and treated for turbidity.     

Capturing Old-Growth Values for Use in Forest Decision-Making

Old-growth forests have declined significantly across the world. Decisions related to old growth are often mired in challenges of value diversity, conflict, data gaps, and resource pressures. This article describes old-growth values of citizens and groups in Nova Scotia, Canada, for integration in sustainable forest management (SFM) decision-making. The study is based on data from 76 research subjects who participated in nine field trips to forest stands. Research subjects were drawn from Aboriginal groups, environmental organizations, forestry professionals, and rural and urban publics. Diaries, group discussions, and rating sheets were used to elicit information during the field trips. Findings show that different elicitation techniques can influence the articulation of intensity with which some values are held. In addition, certain values are more often associated with old-growth than with other forest-age classes. Some values associated with old-growth are considered more important than others, and some silvicultural treatments are perceived to compromise old-growth values more than others. Demographic characteristics, such as constituency group, gender, and age, are shown to influence value priorities. Ideas on how to incorporate old-growth values into SFM decision-making are highlighted.