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.     

Biomechanical Evaluation of a Toggle Pin Technique for Management of Coxofemoral Luxation

Toggle pin stabilization is an accepted technique for the management of coxofemoral (CF) luxation in dogs. The purpose of this study was to determine, in vitro, the respective contributions of several aspects of toggle pin repair to the overall stability of fixation. Factors evaluated were the manner and frequency with which toggle pins oriented on insertion, effect of orientation on toggle pin strength, effect of suture type on ligament prosthesis strength and load sustained by the fixation, and comparison of repair using a modified toggle design to that of capsulorrhaphy. When placed in cadavers using standard technique, conventional toggle pins were found to orient significantly more frequently in one of two possible positions. Mechanical testing of fixations performed in experimentally luxated cadaver hips demonstrated a high (12/20) incidence of toggle pin failure using the conventional implant in the most common orientation. When tested alone, toggle pins were weakest mechanically in this orientation. Rotating the implant 180° increased mean load to failure by 249%. There was no significant difference in load sustained by conventional toggle fixations using No. 2 braided polyester versus 50 lb test monofilament nylon as the suture ligament prosthesis. However, the higher stiffness of the polyester suture may be more favorable for use in this application. Fixation using a toggle rod designed to allow evaluation of construct stability when failure of the toggle is eliminated resulted in an increase in maximum load sustained before luxation (47% of the intact control hips). This load was not significantly different than the resistance to luxation afforded by capsulorrhaphy. This study suggests that when implanting conventional toggle pins, consideration should be given to ensuring placement in the strongest orientation.     

Clinical and Radiographic Evaluation of a Median Sternotomy Technique in the Dog

This study evaluated postoperative sequelae following a sternotomy closed with transsternal and parasternal sutures in nine dogs. Wound complications noted within 30 days suggested excessive intraoperative trauma to bone or surrounding soft tissues. Radiographic evaluation at the end of this period demonstrated a significant lack of osseous bridging between the sternal halves in eight of nine dogs. There was frequent wire breakage, suggesting instability of the sternal halves and considerable midline inaccuracy when splitting the sternum. Postoperative pain was minimal. This technique is suitable for use in dogs provided that swaged-on needles and sufficient transsternal wires are used, the sternebrae are carefully split on the midline, and the wires are carefully twisted to assure a tight closure.     

Stipe necrosis of cultivated mushrooms (Agaricus bisporus) associated with a fluorescent pseudomonad

Pseudomonad bacteria ( Pseudomonas fluorescens ) causing necrosis of the central stipe tissue of Agaricus bisporus are reported for the first time.