Competitive assembly of South Pacific invasive ant communities

Background  

The relative importance of chance and determinism in structuring ecological communities has been debated for nearly a century. Evidence for determinism or assembly rules is often evaluated with null models that randomize the occurrence of species in particular locales. However, analyses of the presence or absence of species ignores the potential influence of species abundances, which have long been considered of major importance on community structure. Here, we test for community assembly rules in ant communities on small islands of the Tokelau archipelago using both presence-absence and abundance data. We conducted three sets of analyses on two spatial scales using three years of sampling data from 39 plots on 11 islands.     

Perceptions of gender dynamics in small‐scale fisheries and conservation areas in the Pursat province of Tonle Sap Lake,Cambodia

The Tonle Sap Lake of Cambodia is one of the most productive ecosystems in the world, supporting millions of small‐scale fisher livelihoods. Women's contributions in these fisheries are often overlooked due to socio‐cultural expectations of roles and responsibilities. This is a crucial omission since climate and anthropogenic influences increasingly threaten lake inhabitants. Addressing these challenges requires the full participation of both men and women who use the lake, thus it is necessary to first understand the social dynamics of these communities. We investigated whether there were differences between men's and women's perceptions of (i) fishing and non‐fishing practices; (ii) power, access and control over fishing resources; and (iii) perceptions towards conservation and conservation areas in Pursat, Cambodia. We interviewed fishers and key informants, and found differences in perceptions of fishing and non‐fishing practices between fishermen and fisherwomen. Men more openly acknowledged unequal power dynamics, access to and control over fishing resources when compared with women. We found contrasting ideas of community fisheries and conservation between men and women, and health and safety challenges they faced in conservation areas. Findings suggest that community perspectives and unequal power relations established specific roles for women that limited their active participation in fisheries management.     

Diversity Analysis of Garlic (Allium sativum L.) Germplasms Available in Nepal Based on Morphological Characters

A total of 179 garlic (Allium sativum L.) accessions were collected from various parts of Nepal in 2000. Each accession was planted in each of a plot of 2.25 m² at the Institute of Agriculture and Animal Science (IAAS) Horticulture farm (225 m asl) and at the Agriculture Research Station, Dailekh (1400 m asl) of Nepal Agriculture Research Council (NARC) in the first week of November 2000. All accessions were characterized for leaf erectness, leaf color, leaf wax, leaf cross section, bulb regularity, bulb skin color, bulb outer scales number, days to emergence, bulbing period, number of green leaves at 135 days after planting, days to maturity, plant height, bulb weight, bulb diameter, number of cloves per bulb, clove diameter and bulb yield. Data were analyzed by using principal component and cluster analysis procedures to reveal three major clusters. Four principal components were identified explaining more than 86% of total variation. Major characters included in the principal components were bulb weight, diameter, yield, number of cloves per bulb, maturity, plant height, number of green leaves at 135 days after planting, and bulbing period. The level of variation found in the collection showed the great potentiality of improving agronomic characters in garlic.     

Reference ranges for biochemical and haematological values in farmed saltwater crocodile (Crocodylus porosus) yearlings

Objective To determine reference ranges for healthy yearling farmed saltwater crocodiles by performing routine biochemical and haematological laboratory tests on blood samples.
Design A clinico-pathological study.
Procedure Blood samples were collected from 120 healthy yearlings from four Northern Territory crocodile farms and body weight and length were measured. All animals had been fasted for 2 days before sample collection. Routine biochemical analytes were determined on 120 samples and haematological values determined on 30 samples (from one farm).
Results Reference ranges for biochemical and haemato-logical values were determined for farmed yearling saltwater crocodiles in the Northern Territory.
Conclusion The results were comparable with published reference ranges for other crocodilian species. Other published results of haematological values from saltwater crocodiles were from very young (6-week-old) hatchlings and older (2- to 4-year-old) crocodiles. Differences in values were presumed to be caused by age-related factors.     

Efficacy of zeta-cypermethrin as pour-on or spray formulations for the control of buffalo fly (Haematobia irritans exigua) in cattle

Objective To determine the efficacy of zeta-cypermethrin in controlling buffalo fly ( Haematobia irritans exigua ).
Design Five field trials in northern and central Queensland.
Procedure Zeta-cypermethrin pour-on at 2.5 mg/kg, spray at 62.5 ppm, deltamethrin pour-on and pour-on vehicle were applied to groups of 20 cattle. Buffalo fly counts were conducted three times before treatment and 3, 7, 14, 21, 28 and 35 days after treatment.
Results In central Queensland where synthetic pyrethroid resistance in buffalo fly populations was rare, 2.5 mg/kg of zeta-cypermethrin pour-on gave good control of buffalo fly for 4 weeks and was better than a deltamethrin product. A zeta-cypermethrin spray used at 62.5 ppm gave 14 days control. In far-north Queensland where resistance to synthetic pyrethroids and heavy rain was common, the maximum period of efficacy of zeta-cypermethrin pour-on was reduced to 2 weeks.
Conclusion In areas where there is low resistance to synthetic pyrethroids among buffalo flies, zeta-cypermethrin pour-on can be expected to give good control for 4 weeks.     

Effects of body condition score (BCS) on steroid‐ and eicosanoid‐metabolizing enzyme activity in various mare tissues during winter anoestrus

The objective of this study was to determine the activity of steroid‐ and eicosanoid‐metabolizing enzymes in horses with varying BCSs. The BCSs of twenty non‐pregnant, anoestrous mares were determined prior to euthanasia, and tissue samples were collected from the liver, kidney, adrenal gland, ovary and endometrium. Cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A) and uridine 5′‐diphospho‐glucuronosyltransferase (UGT) activities were determined using luminogenic substrates. The MIXED procedure of SAS was used to test the effect of BCS on enzyme activity and differences between tissues. Activity of CYP1A in adrenals was increased (p ≤ .05) in BCS 5 versus BCSs 4 and 6. Activity of CYP1A in the liver was increased (p = .05) in BCS 4 versus BCSs 5 and 6. Activity of CYP1A was 100‐fold greater (p < .0001) in the liver than in the adrenal, ovary and kidney. Activity of CYP2C was 100‐fold greater (p < .0001) in the liver than in the adrenal, ovary and endometrium. Activity of CYP3A was only detectable in the liver. Activity of UGT in the kidney was decreased (p = .02) in BCS 4 versus BCSs 5 and 6. Activity of UGT was threefold greater (p < .0001) in the liver than in the kidney, whereas activity of UGT was ninefold greater (p < .0001) in the kidney than in the ovary and endometrium. In general, BCS did not alter the activity of steroid‐ and eicosanoid‐metabolizing enzymes in horses. However, tissue differences in these enzymes indicated abundant hepatic metabolism in horses, which is similar to other livestock species.     

Cell Cycle Stage Analysis of Rabbit Foetal Fibroblasts and Cumulus Cells

Synchronization of the cell cycle stages in G0/G1 phase is one of the key factors determining the success of nuclear transplantation. Serum deprivation, contact inhibition and chemical inhibitors are widely used methods for this purpose. In this study, cell cycle stages of foetal fibroblasts and cumulus cells were determined using flow cytometry [fluorescence-activated cell scan (FACS)]. Foetal fibroblasts (in vitro cultured for 72-120 h) and fresh cumulus cells were analysed in Experiment 1. Fifty to 55% proliferating fibroblasts remained in G0/G1 phase compared with 78% in confluent culture (p <0.05). In contrast to foetal fibroblasts, fresh cumulus cells maintained 90% of the population in the G0/G1 stage. When serum was retrieved from the proliferating fibroblasts from day 1 to day 5 (Experiment 2), proportions of G0/G1 cells increased from the initial ratio of 53 to 87% at day 4 of starvation, which was significantly higher than the non-starved proliferating cells (p <0.05). In Experiment 3, fibroblasts were treated with aphidicolin (0.1 microg/ml, 6 h), demicolcine (0.5 microg/ml, 10 h), or a combination of these two chemicals to synchronize the cell cycle stages. Surprisingly, no differences or significantly lower in the proportions of G0/G1)phase cells were detected (25-50%) compared with the uncontrolled growing cells (53%). These results suggested that fresh cumulus cells rest their cell cycle in G0/G1 stage. Serum deprivation became effective in the first 24 h and reached the highest proportions during days 4-5 after deprivation. Chemical synchronization of the cell cycle stage of rabbit foetal fibroblasts to G0/G1 phase appeared less effective compared to serum deprivation.     

A New Approach to Calculate EMEA��s Predicted Environmental Concentration for Human Pharmaceuticals in Groundwater at Bank Filtration Sites

Hourly concentrations of non-methane hydrocarbons (NMHCs) recorded between June and August 2006, at two monitoring sites (Gijang and Jin) in Busan were analyzed to examine the characteristics and photochemical reactivity of NMHC sources. The two sites represent urban (Jin) and suburban (Gijang) Busan, which is a typical Korean city. Positive matrix factorization (PMF), applied to identify and apportion the sources of NMHCs, revealed nine sources for Gijang and ten sources for Jin. To explore the contribution of each NMHC source to ozone formation at the two sampling sites, the ozone formation potential was estimated for each source. The largest contributors to ozone formation were sources characterized by 1,2,3-trimethylbenzene (26.4%) at Gijang and by toluene, ethylbenzene, and xylenes (22.5%) at Jin, which were composed mostly of heavy hydrocarbons and aromatics. Secondary sources included two coating sources (20.9%, 12.2%) and vehicle exhaust (10.3%) at Gijang and a source represented by toluene (17.4%), vehicle exhaust (15.9%), and a coating-2 source (9.6%) at Jin. Conditional probability function (CPF) and potential source contribution function (PSCF) analysis methods were used to identify the directions of local sources and to locate potential source regions, respectively. The CPF and PSCF results agreed well for the majority of sources resolved by PMF and thus were very useful in identifying the major sources contributing to ozone formation at the two study sites.