Phosphorus composition of manure from swine fed low-phytate grains: evidence for hydrolysis in the animal

Including low-phytic-acid grains in swine diets can reduce P concentrations in manure, but the influence on manure P composition is relatively unknown. To address this we analyzed manure from swine fed one of four barley (Hordeum vulgare L.) varieties. The barley types consisted of wild-type barley (CDC bold, normal barley diet) and three low-phytic-acid mutant barleys that contained similar amounts of total P but less phytic acid. The phytic acid concentrations in the mutant barleys were reduced by 32% (M422), 59% (M635), and 97% (M955) compared with that in the wild-type barley, respectively. Phosphorus concentrations were approximately one-third less in manures from animals fed low-phytic-acid barleys compared with those fed the wild-type variety. Phytic acid constituted up to 55% of the P in feed, but only trace concentrations were detected in NaOH-EDTA extracts of all manures by solution (31)P nuclear magnetic resonance (NMR) spectroscopy. Phosphate was the major P fraction in the manures (86-94% extracted P), with small concentrations of pyrophosphate and simple phosphate monoesters also present. The latter originated mainly from the hydrolysis of phospholipids during extraction and analysis. These results suggest that phytic acid is hydrolyzed in swine, possibly in the hind gut by intestinal microflora before being excreted in feces, even though the animals have little phytase activity in the gut and derive little nutritional benefit from phytate P. We conclude that feeding low-phytic-acid grains reduces total manure P concentrations and the manure P is no more soluble than P generated from normal barley diets.     

The ‘I see you’ prey–predator signal of Apis cerana is innate

An ‘I see you’ (ISY) prey–predator signal can co-evolve when such a signal benefits both prey and predator. The prey benefits if, by producing the signal, the predator is likely to break off an attack. The predator benefits if it is informed by the signal that the prey is aware of its presence and can break off what is likely to be an unsuccessful and potentially costly hunt. Because the signal and response co-evolve in two species, the behaviour underlying an ISY signal is expected to have a strong genetic component and cannot be entirely learned. An example of an ISY signal is the ‘shimmering’ behaviour performed by Asian hive bee workers in the presence of their predator Vespa velutina. To test the prediction that bee–hornet signalling is heritable, we let honey bee workers of two species emerge in an incubator so that they had never been exposed to V. velutina. In Apis cerana, the shimmering response developed 48 h post-emergence, was strong after 72 h and increased further over 2 weeks. In contrast, A. mellifera, which has evolved in the absence of Asian hornets, did not produce the shimmering signal. In control tests, A. cerana workers exposed to a non-threatening butterfly did not respond with the shimmering signal.     

The cues have it; nest-based, cue-mediated recruitment to carbohydrate resources in a swarm-founding social wasp

This study explores whether or not foragers of the Neotropical swarm-founding wasp Polybia occidentalis use nest-based recruitment to direct colony mates to carbohydrate resources. Recruitment allows social insect colonies to rapidly exploit ephemeral resources, an ability especially advantageous to species such as P. occidentalis, which store nectar and prey in their nests. Although recruitment is often defined as being strictly signal mediated, it can also occur via cue-mediated information transfer. Previous studies indicated that P. occidentalis employs local enhancement, a type of cue-mediated recruitment in which the presence of conspecifics at a site attracts foragers. This recruitment is resource-based, and as such, is a blunt recruitment tool, which does not exclude non-colony mates. We therefore investigated whether P. occidentalis also employs a form of nest-based recruitment. A scented sucrose solution was applied directly to the nest. This mimicked a scented carbohydrate resource brought back by employed foragers, but, as foragers were not allowed to return to the nest with the resource, there was no possibility for on-nest recruitment behavior. Foragers were offered two dishes—one containing the test scent and the other an alternate scent. Foragers chose the test scent more often, signifying that its presence in the nest induces naïve foragers to search for it off-nest. P. occidentalis, therefore, employs a form of nest-based recruitment to carbohydrate resources that is mediated by a cue, the presence of a scented resource in the nest.     

Unravelling the molecular mechanism of mutagenic factors impacting human health

Environmental Science and Pollution Research - Environmental mutagens are chemical and physical substances in the environment that has a potential to induce a wide range of mutations and generate...     

Origin of high particle number concentrations reaching the St. Louis, Midwest Supersite

Ultrafine particles are associated with adverse health effects. Total Particle Number Concentration (TNC) of fine particles were measured during 2002 at the St. Louis — Midwest supersite. The time series showed overall low level with frequent large peaks. The time series was analyzed alongside criteria pollutant measurements and meteorological observations. Multiple regression analysis was used to identify further contributing factors and to determine the association of different pollutants with TNC levels. This showed the strong contribution of sulfur dioxide (SO₂) and nitrogen oxides (NO_x) to high TNC levels. The analysis also suggested that increased dispersion resulting from faster winds and higher mixing heights led to higher TNC levels. Overall, the results show that there were intense particle nucleation events in a SO₂ rich plume reaching the site which contributed around 29% of TNC. A further 40% was associated with primary emissions from mobile sources. By separating the remaining TNC by time of day and clear sky conditions, we suggest that most likely 8% of TNC are due to regional nucleation events and 23% are associated with the general urban background.     

Flood risk,climate change and settlement development: a micro-scale assessment of Austrian municipalities

This paper analyses the influence of climate change and land development on future flood risk for selected Austrian flood-prone municipalities. As part of an anticipatory micro-scale risk assessment we simulated four different inundation scenarios for current and future 100- and 300-year floods (which included a climate change allowance), developed scenarios of future settlement growth in floodplains and evaluated changes in flood damage potentials and flood risk until the year 2030. Findings show that both climate change and settlement development significantly increase future levels of flood risk. However, the respective impacts vary strongly across the different cases. The analysis indicates that local conditions, such as the topography of the floodplain, the spatial allocation of vulnerable land uses or the type of land development (e.g. residential, commercial or industrial) in the floodplain are the key determinants of the respective effects of climate change and land development on future levels of flood risk. The case study analysis highlights the general need for a more comprehensive consideration of the local determinants of flood risk in order to increase the effectiveness of an adaptive management of flood risk dynamics.     

Phosphorus in surface runoff from calcareous arable soils of the semiarid Western United States

Management strategies that minimize P transfer from agricultural land to water bodies are based on relationships between P concentrations in soil and runoff. This study evaluated such relationships for surface runoff generated by simulated sprinkler irrigation onto calcareous arable soils of the semiarid western United States. Irrigation was applied at 70 mm h(-1) to plots on four soils containing a wide range of extractable P concentrations. Two irrigation events were conducted on each plot, first onto dry soil and then after 24 h onto wet soil. Particulate P (>0.45 microm) was the dominant fraction in surface runoff from all soils and was strongly correlated with suspended sediment concentration. For individual soil types, filterable reactive P (<0.45 microm) concentrations were strongly correlated with all soil-test P methods, including environmental tests involving extraction with water (1:10 and 1:200 soil to solution ratio), 0.01 M CaCl(2), and iron strips. However, only the Olsen-P agronomic soil-test procedure gave models that were not significantly different among soils. Soil chemical differences, including lower CaCO(3) and water-extractable Ca, higher water-extractable Fe, and higher pH, appeared to account for differences in filterable reactive P concentrations in runoff from soils with similar extractable P concentrations. It may therefore be possible to use a single agronomic test to predict filterable reactive P concentrations in surface runoff from calcareous soils, but inherent dangers exist in assuming a consistent response, even for one soil within a single field.     

CONSUMPTIVE USE OF STREAMFLOW INCREASES IN THE COLORADO RIVER BASIN1

ABSTRACT: This study examined the disposition of streamflow increases that could be created by vegetation management on forest land along the upper reaches of the Colorado River. A network optimization model was used to simulate water flow, storage, consumptive use, and loss within the entire Colorado River Basin with and without the flow increases, according to various scenarios incorporating both current and future consumptive use levels as well as existing and potential institutional constraints. Results indicate that very little of the flow increases would be consumptively used at current use levels, or even at future use levels, if water allocation institutions remain unchanged. Given future use levels and economically based water allocation institutions, up to one-half of the flow increases could be consumptively used. The timing of streamflow increases, and the institutional constraints on water allocation, often limit the potential for consumptive use of flow increases.     

Do international investment contribute to environmental pollution? Evidence from 20 African countries

Environmental Science and Pollution Research - International investment is needed in every economy, and every economy is expected to grow and attract investment. Despite the need of the above in...