Testing landscape metrics as indicators of habitat loss and fragmentation in continuous eucalypt forests (Queensland, Australia)

Landscape metrics are widely applied in landscape ecology to quantify landscape structure. However, many are poorly tested and require rigorous validation if they are to serve as reliable indicators of habitat loss and fragmentation, such as Montreal Process Indicator 1.1e. We apply a landscape ecology theory, supported by exploratory and confirmatory statistical techniques, to empirically test landscape metrics for reporting Montreal Process Indicator 1.1e in continuous dry eucalypt forests of sub-tropical Queensland, Australia. Target biota examined included: the Yellow-bellied Glider (Petaurus australis); the diversity of nectar and sap feeding glider species including P. australis, the Sugar Glider P. breviceps, the Squirrel Glider P. norfolcensis, and the Feathertail Glider Acrobates pygmaeus; six diurnal forest birds species; total diurnal bird species diversity; and the density of nectar-feeding diurnal bird species. Two scales of influence were considered: the stand-scale (2 ha), and a series of radial landscape extents (500 m - 2 km; 78 - 1250 ha) surrounding each fauna transect. For all biota, stand-scale structural and compositional attributes were found to be more influential than landscape metrics. For the Yellow-bellied Glider, the proportion of trace habitats with a residual element of old spotted-gum/ironbark eucalypt trees was a significant landscape metric at the 2 km landscape extent. This is a measure of habitat loss rather than habitat fragmentation. For the diversity of nectar and sap feeding glider species, the proportion of trace habitats with a high coefficient of variation in patch size at the 750 m extent was a significant landscape metric. None of the landscape metrics tested was important for diurnal forest birds. We conclude that no single landscape metric adequately captures the response of the region's forest biota per se. This poses a major challenge to regional reporting of Montreal Process Indicator 1.1e, fragmentation of forest types.

Nomenclature of the GLUT/SLC2A family of sugar/polyol transport facilitators

The recent identification of several additional members of the family of sugar transport facilitators (gene symbol SLC2A, protein symbol GLUT) has created a heterogeneous and, in part, confusing nomenclature. Therefore, this letter provides a summary of the family members and suggests a systematic nomenclature for SLC2A and GLUT symbols.

Overwintering, soil distribution and phenology of Childers canegrub, Antitrogus parvulus (Coleoptera : Scarabaeidae) in Queensland sugarcane

In this study, the question of whether Childers canegrub, Antitrogus parvulus (Britton) overwinters in the subsoil was addressed. Irrigated fields of sugarcane were sampled during a 2-year period near Bundaberg in southern Queensland. Antitrogus parvulus overwintered as second and third instars at each of three sites. During autumn and winter third instars of different allochronic (separated in age by 12 months) populations occurred together and could not be readily separated. Field-collected third instars were reared on ryegrass and separated into two age groups based on the date of pupation. Third instars in the first year of their life cycle (young third instars) remained at shallow depth (100-200 mm) and did not overwinter in the subsoil as once thought. Minimum temperatures during winter were 13-16degreesC and did not prevent young third instars from feeding and gaining weight. Third instars in their second and final year moved downwards from late summer and pupated in the subsoil at 293-425 mm in spring. General phenology was as previously reported with first instar larvae occurring from January until April, second instars from January until November and third instar larvae throughout the year. Prepupae and pupae were found between October and December and adults occurred in soil during November and January. Batches of eggs occurred at a mean depth of 350 mm. First and second instars occurred predominantly at relatively shallow (100-200 mm) depths in the soil profile. All stages tended to be most common under rows of sugarcane rather than in the interrow.

Resistance to Fiji disease in sugar cane: Role of cultivar preference by planthopper vector Perkinsiella saccharicida (Homoptera : Delphacidae)

Fiji disease (FD) of sugar cane caused by Fiji disease virus (FDV) is transmitted by the planthopper Perkinsiella saccharicida Kirkaldy (Hemiptera: Delphacidae). FD is effectively managed by using resistant cultivars, but whether the resistance is for the vector or for the Virus is Unknown. This knowledge would help develop a rapid and reliable glasshouse-based screening method for disease resistance. Sugar cane cultivars resistant, intermediate, and susceptible to FD were screened in a glasshouse, and the relationship between vector preferences and FD incidence was studied. Cultivar preference by nymphs increased with an increase in cultivar susceptibility to FD, but the relationship between adult preference and FD resistance was not significant. There was a positive correlation between the vector population and FD incidence, and the latent period for symptom expression declined with the increase in the vector populations. FD incidence in the glasshouse trial reflected the field-resistance status of sugar cane cultivars with known FD-resistance scores. The results suggest that resistance to FD in sugar cane is mediated by cultivar preference of the plant-hopper vector.

A suite of novel allenes from Australian melolonthine scarab beetles. Structure, synthesis, and stereochemistry

A suite of allenic hydrocarbons, previously unknown as a molecular class from insects, has been characterized from several Australian melolonthine scarab beetles. The allenes are represented by the formula CH3(CH2)nCH=.=CH(CH2)(7)CH3 with n being 11-15, 17 and 19, and thus, all have Delta(9,10)-unsaturation. These structures have been confirmed by syntheses and comparisons of spectral and chromatographic properties with those of the natural components. The enantiomers of (+/-)-Delta(9,10)-tricosadiene and Delta(9,10)-pentacosadiene were separable on a modified beta-cyclodextrin column (gas chromatography), and the natural Delta(9,10)-tricosadiene (n = 11) and Delta(9,10)-pentacosadiene (n = 13) were shown to be of >85% ee. Syntheses of nonracemic allenes of known predominating chirality were acquired using both organotin chemistry and sulfonylhydrazine intermediates, and comparisons then demonstrated that the natural allenes were predominantly (R)-configured.

Amylases in enzyme detergents and their effects on a simulated long-life dairy dessert

Enzyme detergents used in the food industry contain proteinase as the major enzyme but amylase may be present, either by design or inadvertently. Three commercial enzyme detergents and 3 enzyme preparations used in detergents were assayed for alpha-amylase activity by the Ceralpha method using the Megazyme kits. The amylase activities of the detergents varied from 3.2x 10(-6) to 32x 10(-6) mumoles ml(-1) h(-1) while the enzyme preparations had much higher activities ranging from 0.05 to 8.06 mumoles ml(-1) h(-1). When added aseptically to a simulated dairy dessert (2% starch solution) and stored for 42 days, the enzyme detergents caused an increase in viscosity; enzyme preparations at low concentrations caused an initial increase in viscosity followed by a decrease; and enzyme preparations at high concentrations caused an immediate decrease in viscosity. The increase in viscosity corresponded to formation of a distinct network of starch granules while the decrease in viscosity was characterised by a marked decrease in size of the granules and little or no network of granules. Decreases in viscosity corresponded to increases in reducing sugars but samples which increased in viscosity showed no measurable reducing sugars. The amylase activity in all sources was destroyed by heating at 75degreesC for 15 min at pH 1.8.

Heat resistance of Bacillus spores when adhered to stainless steel and its relationship to spore hydrophobicity

Twenty-one strains of Bacillus (10 B. stearothermophilus, 3 B. cereus, and 8 B. licheniformis strains) were assayed for spore surface hydrophobicity on the basis of three measures: contact angle measurement (CAM), microbial adhesion to hydrocarbons (MATH), and hydrophobic interaction chromatography (HIC). On the basis of the spore surface characteristics obtained from these assays, along with data on the heat resistance of these spores in water, eight strains of Bacillus (three B. stearothermophilus, three B. cereus, and two B. licheniformis strains) either suspended in water or adhering to stainless steel were exposed to sublethal heat treatments at 90 to 110degreesC to determine heat resistance (D-value). Significant increases in heat resistance (ranging from 3 to 400%) were observed for the eight strains adhering to stainless steel. No significant correlation was found between these heat resistance increases and spore surface characteristics as determined by the three hydrophobicity assays. There was a significant positive correlation between the hydrophobicity data obtained by the MATH assay and those obtained by the HIC assay, but these data did not correlate with those obtained by the CAM assay.

Effect of storage time and conditions on the seed coat colour of Australian adzuki beans

Two varieties of adzuki beans (Vigna angularis), Bloodwood and Erimo, were stored at temperatures of 10, 20 or 30degreesC, and relative humidities (RH) 40 or 65%, and samples were analysed at 0, 1.5, 3 and 6 months. Storage at 30degreesC for > 1.5 months caused a significant decrease in the a(star) and b(star) colour values and darkening of the seed coat. Beans stored at 65% RH had lower L-star but higher a(star) and b(star) colour values than those stored at 40% RH. Bloodwood and Erimo samples showed similar trends in colour during storage. The best storage conditions for the preservation of the adzuki colour were 10degreesC and 65% RH. The Australian beans had lower L-star, a(star) and b(star) colour values than Japanese Erimo-shouzu beans and storage increased the difference.

Effect of storage time and conditions on the cotyledon cell wall of the adzuki bean (Vigna angularis)

Two varieties of adzuki grown in Australia, Bloodwood and Erimo, were stored for up to 6 months at three temperatures (10, 20 and 30 degreesC), and two relative humidities (RH; 40 and 65%). The amount of cell wall material increased with time under all storage conditions. This increase was greatest at 30 degreesC and 40% RH. Storage time and conditions did not affect the total pectin levels in the cell wall. Erimo constantly exhibited a higher total pectin level than Bloodwood. The Bloodwood soluble pectin, Ca++ and Mg++ and Erimo Ca++ in the cell wall remained stable during storage, while the Erimo soluble pectin and Mg++ exhibited a slight decrease at 20 and 30 degreesC after 3 months of storage. (C) 2002 Elsevier Science Ltd. All rights reserved.

In situ characterization of stickiness of sugar-rich foods using a linear actuator driven stickiness testing device

A stickiness testing device based on the probe tack test has been designed and tested. It was used to perform in situ characterization of drying hemispherical drops with an initial radius 3.5 mm. Tests were carried out in two drying temperatures, 63 and 95 degreesC. Moisture and temperature histories of the drying drops of fructose, honey, sucrose, maltodextrin and sucrose-maltodextrin mixtures were determined. The rates of moisture evaporation of the fructose solution was the fastest while those of the maltodextrin solution was the lowest. A profile reversal was observed when the temperature profiles of these materials were compared. Different modes of failure were observed during the stickiness tests. Pure fructose and honey solutions remained completely sticky and failed cohesively until the end of drying. Pure sucrose solution remained sticky and failed cohesively until complete crystallization occurred. The surface of the maltodextrin drops formed a skin shortly after the start of drying. It exhibited adhesive failure and reached a state of non-adhesion. Addition of maltodextrin significantly altered the stickiness of sucrose solution. (C) 2002 Elsevier Science Ltd. All rights reserved.

Surface stickiness of drops of carbohydrate and organic acid solutions during convective drying: Experiments and modeling

Drying kinetics of low molecular weight sugars such as fructose, glucose, sucrose and organic acid such as citric acid and high molecular weight carbohydrate such as maltodextrin (DE 6) were determined experimentally using single drop drying experiments as well as predicted numerically by solving the mass and heat transfer equations. The predicted moisture and temperature histories agreed with the experimental ones within 6% average relative (absolute) error and average difference of +/- 1degreesC, respectively. The stickiness histories of these drops were determined experimentally and predicted numerically based on the glass transition temperature (T-g) of surface layer. The model predicted the experimental observations with good accuracy. A nonsticky regime for these materials during spray drying is proposed by simulating a drop, initially 120 mum in diameter, in a spray drying environment.

Genetic characterization of pilin glycosylation and phase variation in Neisseria meningitidis

Pili of Neisseria meningitidis are a key virulence factor, being the major adhesin of this capsulate organism and contributing to specificity for the human host. Pili are post-translationally modified by addition of either an O-linked trisaccharide, Gal (beta1-4) Gal (alpha1-3) 2,4-diacetamido-2,4,6-trideoxyhexose or an O-linked disaccharide Gal (alpha1,3) GlcNAc. The role of these structures in meningococcal pathogenesis has not been resolved. In previous studies we identified two separate genetic loci, pglA and pglBCD, involved in pilin glycosylation. Putative functions have been allocated to these genes; however, there are not enough genes to account for the complete biosynthesis of the described structures, suggesting additional genes remain to be identified. In addition, it is not known why some strains express the trisaccharide structure and some the disaccharide structure. In order to find additional genes involved in the biosynthesis. of these structures, we used the recently published group A strain Z2491 and group B strain MC58 Neisseria meningitidis genomes and the unfinished Neisseria meningitidis group C strain FAM18 and Neisseria gonorrhoeae strain FA1090 genomes to identify novel genes involved in pilin glycosylation, based on homology to known oligosaccharide biosynthetic genes. We identified a new gene involved in pilin glycosylation designated pglE and examined four additional genes pgIB/B2, pglF, pglG and pglH. A strain survey revealed that pglE and pglF were present in each strain examined. The pglG, pglH and pgIB2 polymorphisms were not found in strain C311#3 but were present in a large number of clinical isolates. Insertional mutations were constructed in pglE and pglF in N. meningitidis strain C311#3, a strain with well-defined lipopolysaccharide (LPS) and pilin-linked glycan structures. Increased gel migration of the pilin subunit molecules of pglE and pglF mutants was observed by Western analysis, indicating truncation of the trisaccharide structure. Antisera specific for the C311#3 trisaccharide failed to react with pilin from these pglE and pglF mutants. GC-MS analysis of the sugar composition of the pglE mutant showed a reduction in galactose compared with C311#3 wild type. Analysis of amino acid sequence homologies has suggested specific roles for pglE and pglF in the biosynthesis of the trisaccharide structure. Further, we present evidence that pglE, which contains heptanucleotide repeats, is responsible for the phase variation between trisaccharide and disaccharide structures in strain C311#3 and other strains. We also present evidence that pglG, pglH and pgIB2 are potentially phase variable.