Multi Pattern Dynamic Time Warping For Automatic Speech Recognition

We are addressing the problem of jointly using multiple noisy speech patterns for automatic speech recognition (ASR), given that they come from the same class. If the user utters a word K times, the ASR system should try to use the information content in all the K patterns of the word simultaneously and improve its speech recognition accuracy compared to that of the single pattern based speech recognition. T address this problem, recently we proposed a Multi Pattern Dynamic Time Warping (MPDTW) algorithm to align the K patterns by finding the least distortion path between them. A Constrained Multi Pattern Viterbi algorithm was used on this aligned path for isolated word recognition (IWR). In this paper, we explore the possibility of using only the MPDTW algorithm for IWR. We also study the properties of the MPDTW algorithm. We show that using only 2 noisy test patterns (10 percent burst noise at -5 dB SNR) reduces the noisy speech recognition error rate by 37.66 percent when compared to the single pattern recognition using the Dynamic Time Warping algorithm.

Buoyancy and germination of pond apple (Annona glabra L.) propagules in fresh and salt water

Stephen Setter, Melissa Setter, Michael Graham and Joe Vitelli recently published their paper 'Buoyancy and germination of pond apple (Annona glabra L.) propagules in fresh and salt water' in Proceedings of the 16th Australian Weeds Conference. Stephen also presented this paper at the conference. Pond apple is an aggressive woody weed which has invaded many wetlands, drainage lines and riparian systems across the Wet Tropics bioregion of Far North Queensland. Most fruit and seed produced by pond apple during the summer wet season fall directly into creeks, river banks, flood plains and swamps from where they are dispersed. They reported that pond apple seeds can float for up to 12 months in either fresh or salt water, with approximately 38% of these seeds germinating in a soil medium once removed from the experimental water tanks at South Johnstone. Their study suggested that the removal of reproductive trees from areas adjacent to creeks and rivers will have an immediate impact on potential spread of pond apple by limiting seed input into flowing water bodies.

Cassowary dispersal of the invasive pond apple in a tropical rainforest: the contribution of subordinate dispersal modes in invasion.

Dispersal is a significant determinant of the pattern and process of invasions; however, weed dispersal distances are rarely described and descriptions of dispersal kernels are completely lacking for vertebrate-dispersed weeds. Here, we describe dispersal kernels generated by a native disperser, the endangered southern cassowary (Casuarius casuarius, L.) for an invasive, tropical rainforest plant, pond apple (Annona glabra, L.). Pond apple is primarily water-dispersed and is managed as such. We consider whether cassowary dispersal, as a numerically subordinate dispersal mode, provides an additional dispersal service that may modify the invasion process. In infested areas, pond apple seed was common in cassowary dung. Gut passage had no effect on the probability of single seed germination but deposition in clumps or as whole fruits reduced the probability of germination below that of single seeds. Gut passage times ranged from 65 to 1675 min. Combined with cassowary movement data, this resulted in estimated dispersal distances of 12.5-5212 m, with a median distance of 387 m (quartile range 112-787 m). Native frugivores can be effective dispersers of weeds in rainforest and even terrestrial dispersers can provide long-distance dispersal. Importantly, though pond apple might be expected to be almost entirely dispersed downstream and along the margins of aquatic and marine habitats, cassowaries provide dispersal upstream and between drainages, leading to novel dispersal outcomes. Even through the provision of small quantities of novel dispersal outcomes, subordinate dispersal modes can play a significant role in determining invasion pattern and influence the ultimate success of control programs by providing dispersal to locations unattainable via the primary mode.

Germination of Hymenachne amplexicaulis and H. acutigluma under contrasting light, temperature and nitrate regimes

A laboratory experiment compared germination of the invasive exotic grass Hymenachne amplexicaulis (Rudge) Nees and the native H. acutigluma (Steud.) Gilliland. Seeds of both species were exposed to combinations of light (constant dark, alternating dark/light or constant light), temperature (constant or alternating) and nitrate regimes (with or without the addition of KNO3). Three seed lots of H. amplexicaulis (fresh, two adn four months old) and one of H. acutigluma (fresh seed) were tested. A significant temperature x light x nitrate x seed lot interaction occured. At a constant temperature very few seeds of either H. amplexicaulis or H. acutigluma germinated, regardless of the light regime or addition of KNO3. Generally, maximum germination occurred under a combination of alternating temperature, the presence of light (either constant or alternating) and the addition of KNO3. The exception was four month stored H. amplexicaulis seed, which reached maximum germinaction without the need for KNO3. Fresh seed of both H. amplexicaulis and H. acutigluma exhibited similar germination requirements. These findings suggest that conditions that buffer seeds from light and/or temperature fluctuations could reduce germination and possibly extend the life of seed banks of both H. amplexicaulis and H. acutigluma. Conversely, for land managers trying to control the exotic H. amplexicaulis, activities that create more favourable conditions for germination may help deplete seed banks faster.

What lies beneath? The pattern and abundance of the subterranean tuber bank of the invasive liana cat's claw creeper, Macfadyena unguis-cati (Bignoniaceae)

Cat’s claw creeper, Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) is a major environmental weed of riparian areas, rainforest communities and remnant natural vegetation in coastal Queensland and New South Wales, Australia. In densely infested areas, it smothers standing vegetation, including large trees, and causes canopy collapse. Quantitative data on the ecology of this invasive vine are generally lacking. The present study examines the underground tuber traits of M. unguis-cati and explores their links with aboveground parameters at five infested sites spanning both riparian and inland vegetation. Tubers were abundant in terms of density (~1000 per m2), although small in size and low in level of interconnectivity. M. unguis-cati also exhibits multiple stems per plant. Of all traits screened, the link between stand (stem density) and tuber density was the most significant and yielded a promising bivariate relationship for the purposes of estimation, prediction and management of what lies beneath the soil surface of a given M. unguis-cati infestation site. The study also suggests that new recruitment is primarily from seeds, not from vegetative propagation as previously thought. The results highlight the need for future biological-control efforts to focus on introducing specialist seed- and pod-feeding insects to reduce seed-output.

Validating economic and environmental sustainability of a short-term summer forage legume in dryland wheat cropping systems in south-west Queensland.

The present study set out to test the hypothesis through field and simulation studies that the incorporation of short-term summer legumes, particularly annual legume lablab (Lablab purpureus cv. Highworth), in a fallow-wheat cropping system will improve the overall economic and environmental benefits in south-west Queensland. Replicated, large plot experiments were established at five commercial properties by using their machineries, and two smaller plot experiments were established at two intensively researched sites (Roma and St George). A detailed study on various other biennial and perennial summer forage legumes in rotation with wheat and influenced by phosphorus (P) supply (10 and 40 kg P/ha) was also carried out at the two research sites. The other legumes were lucerne (Medicago sativa), butterfly pea (Clitoria ternatea) and burgundy bean (Macroptilium bracteatum). After legumes, spring wheat (Triticum aestivum) was sown into the legume stubble. The annual lablab produced the highest forage yield, whereas germination, establishment and production of other biennial and perennial legumes were poor, particularly in the red soil at St George. At the commercial sites, only lablab-wheat rotations were experimented, with an increased supply of P in subsurface soil (20 kg P/ha). The lablab grown at the commercial sites yielded between 3 and 6 t/ha forage yield over 2-3 month periods, whereas the following wheat crop with no applied fertiliser yielded between 0.5 to 2.5 t/ha. The wheat following lablab yielded 30% less, on average, than the wheat in a fallow plot, and the profitability of wheat following lablab was slightly higher than that of the wheat following fallow because of greater costs associated with fallow management. The profitability of the lablab-wheat phase was determined after accounting for the input costs and additional costs associated with the management of fallow and in-crop herbicide applications for a fallow-wheat system. The economic and environmental benefits of forage lablab and wheat cropping were also assessed through simulations over a long-term climatic pattern by using economic (PreCAPS) and biophysical (Agricultural Production Systems Simulation, APSIM) decision support models. Analysis of the long-term rainfall pattern (70% in summer and 30% in winter) and simulation studies indicated that ~50% time a wheat crop would not be planted or would fail to produce a profitable crop (grain yield less than 1 t/ha) because of less and unreliable rainfall in winter. Whereas forage lablab in summer would produce a profitable crop, with a forage yield of more than 3 t/ha, ~90% times. Only 14 wheat crops (of 26 growing seasons, i.e. 54%) were profitable, compared with 22 forage lablab (of 25 seasons, i.e. 90%). An opportunistic double-cropping of lablab in summer and wheat in winter is also viable and profitable in 50% of the years. Simulation studies also indicated that an opportunistic lablab-wheat cropping can reduce the potential runoff+drainage by more than 40% in the Roma region, leading to improved economic and environmental benefits.

Effect of foliar herbicides on the germination and viability of Siam weed (Chromolaena odorata) seeds located on plants at the time of application.

This paper reports a field study undertaken to determine if the foliar application of herbicides fluroxypyr (150 mL 100 L-1 a.i.) and metsulfuron-methyl (12 g 100 L-1 a.i.) were capable of reducing the germination and viability of Chromolaena odorata (L.) R.M.King & H.Rob. (Siam weed) seeds at three different stages of maturity. After foliar application of fluroxypyr germination of mature seeds was reduced by 88% and intermediate and immature seeds were reduced by 100%, compared to the control. Fluroxypyr also reduced the viability of mature, intermediate and immature seeds by 79, 89 and 67% respectively, compared to the control. Metsulfuron-methyl reduced germination of intermediate and immature seeds by 53 and 99% respectively compared to the control. Viability was also reduced by 74 and 96% respectively, compared to the control. Mature seeds were not affected by metsulfuron-methyl as germination and viability increased by 2% and 1% respectively, as compared to the control. These results show that these herbicides are capable of reducing the amount of viable seed entering the seed bank. However depending on the treatment and stage of seed development a percentage of seeds on the plants will remain viable and contribute to the seed bank. This information is of value to Siam weed eradication teams as plants are most easily located and subsequently treated at the time of flowering. Knowledge of the impact of control methods on seeds at various stages of development will help determine the most suitable chemical control option for a given situation.

Timing of infection of macadamia fruit by Pseudocercospora macadamiae and climatic effects on growth and spore germination.

Pseudocercospora macadamiae causes husk spot of macadamia. Husk spot control would be improved by verifying the stages in fruit development susceptible to infection, and determine some of the climatic conditions likely to lead to high disease pressure periods in the field. Our results showed that the percent conidia germination and growth of germ tubes and mycelia of P. macadamiae were greatest at 26 degrees C, with better conidia germination associated with high relative humidity and free water. The exposure of match-head-sized and pea-sized fruit stages to natural P. macadamiae inoculum in the field led to 2 5-fold increases in husk spot incidence, and up to 8.5-fold increases in premature abscission, compared with unexposed fruit. Exposure of fruit stages later than match-head-sized and pea-sized fruit generally caused no further increases in disease incidence or premature abscission. Climatic conditions were found to have a strong influence on the behaviour of P. macadamiae, the host, oil accumulation, and the subsequent impact of husk spot on premature abscission. Our findings suggest that fungicide application should target fruit at the match-head-sized stage of development in order to best reduce yield losses, particularly in seasons where oil accumulation in fruit is prolonged and climatic conditions are optimal for P. macadamiae.

Cinnamate toxicity expression on phenylalanine ammonia-lyase activity, germination and growth of cucumber (Cucumis sativis) seedlings

Cinnamate is the product of phenylalanine ammonialyase (PAL). This compound, a precursor of phenolics in plants, has been shown to be phytotoxic. Cinnamate inhibits PAL activity in cucumber seedlings. DL-phenylalanine has the same effect on the enzyme but does not affect growth. Actinomycin D and cycloheximide are phytotoxic and inhibit PAL. Production of a double-peg has been noticed in the seedlings, grown in the presence of actinomycin D. Light stimulates PAL activity in the seedling.

Germination, emergence, and persistence of Sonchus oleraceus, a major crop weed in subtropical Australia.

Sonchus oleraceus (common sowthistle) is a dominant weed and has increased in prevalence in conservation cropping systems of the subtropical grain region of Australia. Four experiments were undertaken to define the environmental factors that favor its germination, emergence, and seed persistence. Seeds were germinated at constant temperatures between 5 and 35C and water potentials between 0 and -1.4 MPa. The maximum germination rate of 86-100% occurred at 0 and -0.2 MPa, irrespective of the temperature when exposed to light (12 h photoperiod light/dark), but the germination rate was reduced by 72% without light. At water potentials of -0.6 to -0.8 MPa, the germination rate was reduced substantially by higher temperatures; no seed germinated at a water potential >-1.0 MPa. Emergence and seed persistence were measured over 30 months following seed burial at 0 (surface), 1, 2, 5, and 10 cm depths in large pots that were buried in a south-eastern Queensland field. Seedlings emerged readily from the surface and 1 cm depth, with no emergence from below the 2 cm depth. The seedlings emerged during any season following rain but, predominantly, within 6 months of planting. Seed persistence was short-term on the soil surface, with 2% of seeds remaining after 6 months, but it increased with the burial depth, with 12% remaining after 30 months at 10 cm. Thus, a minimal seed burial depth with reduced tillage and increased surface soil water with stubble retention has favored the proliferation of this weed in any season in a subtropical environment. However, diligent management without seed replenishment will greatly reduce this weed problem within a short period.

New reagents 3: aluminium iodide - a highly regioselective ether-cleaving reagent with novel cleavage pattern

AlI3 is an easily accessible and versatile ether-cleaving reagent.

Spatial and diurnal pattern of protein foraging by Bactrocera tryoni (Froggatt) on a host plant

Background: Queensland fruit fly, Bactrocera tryoni, is the major pest fruit fly in Australia. Protein bait sprays, where insecticides are mixed with spot applications of a protein based food lure, are one of the sustainable pre-harvest fruit fly management strategies used in Australia. Although protein bait sprays do manage fruit fly infestation in the field, there is little science underpinning this technique and so improving its efficacy is difficult. Lacking information includes where and when to apply protein bait in order to best target foraging B. tryoni. As part of new work in this area, we investigated the effect of height of protein on tree and host plant fruiting status on the spatial and temporal protein foraging patterns of B. tryoni. MEthod: The work was conducted in the field using nectarine and guava plants and wild B. tryoni at Redland Bay, Queensland, Australia. Spot sprays of protein bait were applied to the foliage of randomly selected fruiting and non-fruiting trees. Each tree received protein bait spot sprays on the lower and higher foliage at 0530hrs. The number, sex and species of flies that fed on each protein spot were recorded hourly from 0600hrs through to 1800hrs.Results: For nectarines, there was a significant difference in the number of B. tryoni feeding on protein bait placed at different locations within the tree (ANOVA, F = 8.898, p = 0.001). More flies fed on protein placed on higher foliage relative to lower, irrespective of the fruiting status of the nectarine trees. A significant difference was also observed in the diurnal protein feeding pattern of B. tryoni (ANOVA, F = 2.164, p = 0.024), with more flies feeding at 1600hrs. Results for guava are still being collected and will be presented at the meeting.Conclusions: We conclude that B. tryoni effectively forages for protein at heights higher than 1.3m from ground, indicating greater efficacy of protein bait when applied at foliage higher in the canopy. Bactrocera tryoni actively forages for protein throughout the day, with a highest feeding peak at 1600hrs. The lack of significant difference in the spatial protein foraging pattern between fruiting and non-fruiting nectarine trees may be a real result, or may have resulted from the fruiting tree being very close (within 1 – 2 metres) of the non-fruiting tree. This hypothesis is being tested in the guava trial.

Susceptibility variants for male-pattern baldness on chromosome 20p11

We carried out a genome-wide association study in 296 individuals with male-pattern baldness (androgenetic alopecia) and 347 controls. We then investigated the 30 best SNPs in an independent replication sample and found highly significant association for five SNPs on chromosome 20p11 (rs2180439 combined P = 2.7 x 10(-15)). No interaction was detected with the X-chromosomal androgen receptor locus, suggesting that the 20p11 locus has a role in a yet-to-be-identified androgen-independent pathway.

A four-variable model for the pattern-forming mechanism in Hydra

A generalized Gierer-Meinhardt model has been used to account for the transplantation experiments in Hydra. In this model, a cross inhibition between the two organizing centres (namely, head and foot) are assumed to be the only mode of interaction in setting up a stable morphogen distribution for the pattern formation in Hydra.