Deposition and solubility of airborne metals to four plant species grown at varying distances from two heavily trafficked roads in London

In urban areas, a highly variable mixture of pollutants is deposited as particulate matter. The concentration and bioavailability of individual pollutants within particles need to be characterised to ascertain the risks to ecological receptors. This study, carried out at two urban parks, measured the deposition and water-solubility of metals to four species common to UK urban areas. Foliar Cd, Cr, Cu, Fe, Ni, Pb and Zn concentrations were elevated in at least one species compared with those from a rural control site. Concentrations were, however, only affected by distance to road in nettle and, to a lesser extent, birch leaves. Greater concentrations of metal were observed in these species compared to cypress and maple possibly due to differences in plant morphology and leaf surfaces. Solubility appeared to be linked to the size fraction and, therefore, origin of the metal with those present predominantly in the coarse fraction exhibiting low solubility.     

Characterization of isolated yeast growth response to methionine analogs

Methionine is one of the first limiting amino acids in poultry nutrition. The use of methionine-rich natural feed ingredients, such as soybean meal or rapeseed meal may lead to negative environmental consequences. Amino acid supplementation leads to reduced use of protein-rich ingredients. The objectives of this study were isolation of potentially high content methionine-containing yeasts, quantification of methionine content in yeasts and their respective growth response to methionine analogs. Minimal medium was used as the selection medium and the isolation medium of methionine-producing yeasts from yeast collection and environmental samples, respectively. Two yeasts previously collected along with six additional strains isolated from Caucasian kefir grains, air-trapped, cantaloupe, and three soil samples could grow on minimal medium. Only two of the newly isolated strains, K1 and C1, grew in minimal medium supplied with either methionine analogs ethionine or norleucine at 0.5% (w/v). Based on large subunit rRNA sequences, these isolated strains were identified as Pichia udriavzevii/Issatchenkia orientalis. P. kudriavzevii/I. orentalis is a generally recognized as a safe organism. In addition, methionine produced by K1 and C1 yeast hydrolysate yielded 1.3 ± 0.01 and 1.1 ± 0.01 mg g^?1 dry cell. Yeast strain K1 may be suitable as a potential source of methionine for dietary supplements in organic poultry feed but may require growth conditions to further increase their methionine content.     

Communal nursing in the evening bat,Nycticeius humeralis

Summary Nursing observations over two summers involving 76 lactating female evening bats, Nycticeius humeralis, and 128 pups in an attic in northern Missouri indicate that communal nursing occurs rarely until 2 weeks before weaning during which time over 18% of nursing bouts involve nondescendant offspring. The average relatedness among female pairs nursing non-descendant offspring, based on identity-by-descent estimates using allozyme data, was 0.04 (SE=0.12). Mitochondrial DNA d-loop sequence comparisons confirm that at most only 2 of 20 female pairs nursing non-descendant offspring came from the same matriline. Thus, females do not nurse matrilineal kin preferentially despite female natal philopatry. In addition, the average degree of relatedness within a colony (r=0.01, SE =0.03) is too low to provide any indirect benefits from communal nursing. Female error alone is insufficient to explain these observations because females tended to allow female nondescendant young to nurse but excluded nondescendant males, particularly when they had all-male litters. Furthermore, communal nursing bouts did not differ in duration from parental nursing bouts and involved 31 % of all banded females and 24% of all banded pups observed nursing. Communal nursing occurred most frequently when pups began hunting on their own and when lactating females attained their lowest average pre-fed body weight. Mortality during this period was higher for male than female pups, and relative weights implicate starvation as the cause. Time-lapse video records of four families of bats in captivity showed that the number of nursing bouts was proportional to daily weight change. I propose that these results are consistent with both immediate and delayed benefits accruing to females which experience variable hunting success. If a female with extra milk reduced her weight by dumping milk prior to her next foraging trip, she could obtain an immediate energetic benefit and maintain maximum milk production. By restricting such milk donations to nondescendant females she may also increase colony size and thereby enhance her future acquisition of information about foraging and roosting sites.     

Conflict and Impacts of Divers and Anglers in a Marine Park

The New South Wales State Government (Australia) gazetted the Jervis Bay Marine Park (JBMP) in 1998. During the preparation of the draft zoning plan in 2000, societal data on two conflicting park user groups—recreational scuba divers and fishers (anglers)—was collected. While conflict resolution was a plan priority, other factors, such as cumulative environmental impacts of users and protection for the critically endangered grey nurse shark (Carcharias taurus), further complicated planning. Both scuba diving and angling are primary summer activities and are disproportionately concentrated around the headlands of the bay. Furthermore, shore based game-fishing was concentrated on the northern headland, where the conflict was centered. However, when the exact locations of divers and anglers were determined, there was a partial partitioning of the available space, with only a small contested overlap. To resolve conflict and maximize positive environmental outcomes, a sanctuary zone and no-anchoring zone option in the draft zoning plan was sought to formalize this partition. The human dimension data proved valuable in guiding environmental management in this politically volatile situation. A baseline study conducted 11 years previously was also used to gain a limited perspective on change in user numbers. Comparison between study periods indicated dive numbers had remained similar, while the number of dive charter trips was significantly less. The numbers of anglers, for the four months compared, had doubled and tripled. The actual data used to inform management is presented and the limitations of this best available data approach are discussed.     

Sub-regional integration in Sudan: the key to food security and recovery

The signing of the Comprehensive Peace Agreement (CPA) in Sudan has created a new opportunity for peace. Approaches to food security must now be reoriented based on the agro-ecological diversity in Sudan. WFP is in a unique position to catalyse an approach to food security that meets immediate needs and contributes to long-term recovery, in collaboration with the Government of National Unity (GNU) and the Government of South Sudan (GOSS). Aggregate food production in Sudan has increased in the past decade. At sub-regional levels, however, many areas remain food insecure. Major research must be undertaken to identify optimum levels of food production and barriers to access to food at sub-regional levels as a first step towards linking deficit areas with areas of surplus. Initiatives must also be undertaken to facilitate increased integration between sub-regions. Increased sub-regional linkages could ensure more efficient delivery of food in the short term as well as recovery and economic growth in the long term.     

Copulation duration and sperm precedence in the stalk-eyed fly Cyrtodiopsis whitei (Diptera : Diopsidae)

Summary By means of field observations and laboratory experiments on the Malaysian stalk-eyed fly Cyrtodiopsis whitei we examined the consequences of variation in copulation duration for sperm competition. In this sexually dimorphic species over 90% of all copulations occur in nocturnal aggregations with from one to four males and up to 24 females. Copulation duration observed in both the field and the laboratory exhibited a bimodal distribution with peaks at 10 and 50 s. In the field short copulations less than 30 s long occurred frequently when more than one male was present in an aggregation but most were not the direct result of male interference. Sperm counts from female spermathecae after artificial interruptions indicated sperm are not transferred during the first 40 s of a copulation. When solitary males mated up to five times in succession to virgin females, short copulations did not occur, nor was the number of sperm transferred reduced. However, short copulations did occur when we mated isolated females within 6 min of a previous copulation. By mating irradiated and non-irradiated males in reciprocal pairs we discovered that C. whitei exhibits both first-male sperm precedence and sperm mixing. More than half of the females mated first to sterile and then to fertile males failed to produce offspring. Such variation in copulation duration and sperm precedence is consistent with male placement and detection of a spermatophore that acts as a temporary mating plug. Our data suggest that those male C. whitei which successfully defend large aggregations of females reduce sperm waste and competition by preferentially transferring sperm to females that have not mated recently. Correspondence to: G.S. Wilkinson     

Modelling the photosynthetic production by sponges on Davies Reef,Great Barrier Reef

Sponge populations on Australia's Great Barrier Reef (GBR) may contain a mix of both phototrophic and heterotrophic species. The distribution of many of these sponges on reefs is assumed to be determined by light. A model was developed to investigate how the distribution of phototrophic sponges over depth is restricted by the availability of photosynthetically active radiation. Estimates of the balance between photosynthetic production and the total respiratory demand of entire sponge communities on Davies Reef (a middle-shelf reef of the Great Barrier Reef) are provided. These estimates are based upon published data for community composition and biomass, whilst photokinetic parameters have been determined for a variety of sponge species from oxygenexchange measurements. Phototrophic sponges on the fore-reef slope are predicted to exist at or above a state of net 24 h compensation (i.e., photosynthetic oxygen production by sponges balances or exceeds respiration over a 24 h period) to a depth of 30 m. It is proposed that phototrophic sponges are obligate phototrophs because the availability of light for photosynthesis corresponds with the lower depth limit of their distribution. Sponge communities (including both phototrophs and heterotrophs) from the fore-reef and lagoon exist close to a state of net 24 h compensation to a depth of 10 to 15 m. This balance shows diurnal variations, associated with the activity of phototrophs, such that instantaneous compensation of the community may occur to depths of 20 to 25 m when light is maximal.