The Effect of Flow Regulation on Channel Geomorphic Unit (CGU) Composition in the Soča River, Slovenia.

This paper sets out to examine the effects of flow regulation on the size, spatial distribution and connectivity of physical habitats or channel geomorphic units (CGU) of an upland river system in Slovenia. A river channel survey was completed along three reaches (totalling 14.3km) of the Soča River in order compare an unregulated stretch (reach 1), with two regulated reaches with lower discharges, i.e. a bypassed section that experiences significant flow reduction (reach 2), and a stretch regulated by dam operation (reach 3). CGU’s were classified according to a modified version of the Hawkins et al (1993) system, and mapped on foot and from a boat using a combination of visual assessment and physical measurement. Mapping-grade GPS was used to locate CGU boundaries to sub-metre accuracy, and the application of GIS (MapInfo) enabled the description and analysis of the longitudinal distribution of CGU’s along each reach. Results demonstrated significant differences in the CGU composition between the unregulated and regulated reaches. The unregulated stretch (reach 1) was dominated by the glides (55%) with relatively fast-flowing and turbulent features (runs, riffles and rapids) making up the rest of the reach. The dominant feature of both of the regulated reaches were the slow flowing pool CGU’s occupying 44% of the bypassed section (reach 2), and 76% of the dam regulated section (reach 3), with glides, runs, riffles and rapids forming the remainder of the CGU’s. Physical measurements highlighted the extent to which the reduced discharge in the regulated reaches was dewatering the channel and reducing the size of the CGU’s. The average CGU size in the unregulated stretch (reach 1) was 58m2 of water area per m of channel length (m2/m) compared to 18.42m2/m in the reach 2, and 29.22m2/m in reach 3. CGU’s tended to be shorter, and hence there was greater habitat division or fragmenta-tion evident in the two regulated reaches, particularly the bypassed section. For example, there were on aver-age 6.81 CGU’s per km in the unregulated reach (reach 1), 18.12 CGU/km in reach 2, and 8.08 CGU/km in reach 3. This study suggests that in the Soča River under the flow conditions present during the survey, flow regula-tion alters the dominant types of CGU’s present (to slower flowing and less turbulent features), significantly reduces the size of CGU’s, and affects the longitudinal distribution of types by reducing habitat connectivity and creating greater habitat fragmentation

The Effect of Flow Regulation on the Spatial Distribution and Dynamics of Channel Geomorphic Units (CGU’s) in the Soča River, Slovenia.

This research examines the impact of flow regulation on the spatial distribution and dynamics of physical habitats or channel geomorphic units (CGU) of the Soca River, an upland river system in Slovenia. In order to assess the impact of flow alteration on the spatial pattern of CGU type, size, hydraulics and distribution, a river channel survey was completed along three reaches (totalling 14.3km), i.e. an unregulated stretch and two regulated reaches (with reduced flows). In addition, one regulated reach was re-surveyed at different discharges to investigate the dynamics of CGU’s and their relationship with flow. CGU’s were classified and mapped on foot and from a boat using a combination of visual assessment and physical measurements of velocity and depth in each CGU. Mapping-grade GPS was used to locate CGU boundaries to sub-metre accuracy, and the application of GIS (MapInfo) enabled the description and analysis of the longitudinal distribution of CGU’s along each reach. The effect of flow regulation on the hydraulic character of the river becomes apparent by highlighting significant differences in the dominant types of CGU’s present between the regulated and unregulated reaches. Reduced flows from river regulation also significantly reduces the size of CGU’s, alters their hydraulic character, and affects the longitudinal distribution of types by creating greater habitat fragmentation. This work also highlights the need to assess CGU’s along continuous stretches of river in order to understand the nature and dynamics of river habitats

The impact of the Lombard effect on audio and visual speech recognition systems

When producing speech in noisy backgrounds talkers reflexively adapt their speaking style in ways that increase speech-in-noise intelligibility. This adaptation, known as the Lombard effect, is likely to have an adverse effect on the performance of automatic speech recognition systems that have not been designed to anticipate it. However, previous studies of this impact have used very small amounts of data and recognition systems that lack modern adaptation strategies. This paper aims to rectify this by using a new audio-visual Lombard corpus containing speech from 54 different speakers – significantly larger than any previously available – and modern state-of-the-art speech recognition techniques. The paper is organised as three speech-in-noise recognition studies. The first examines the case in which a system is presented with Lombard speech having been exclusively trained on normal speech. It was found that the Lombard mismatch caused a significant decrease in performance even if the level of the Lombard speech was normalised to match the level of normal speech. However, the size of the mismatch was highly speaker-dependent thus explaining conflicting results presented in previous smaller studies. The second study compares systems trained in matched conditions (i.e., training and testing with the same speaking style). Here the Lombard speech affords a large increase in recognition performance. Part of this is due to the greater energy leading to a reduction in noise masking, but performance improvements persist even after the effect of signal-to-noise level difference is compensated. An analysis across speakers shows that the Lombard speech energy is spectro-temporally distributed in a way that reduces energetic masking, and this reduction in masking is associated with an increase in recognition performance. The final study repeats the first two using a recognition system training on visual speech. In the visual domain, performance differences are not confounded by differences in noise masking. It was found that in matched-conditions Lombard speech supports better recognition performance than normal speech. The benefit was consistently present across all speakers but to a varying degree. Surprisingly, the Lombard benefit was observed to a small degree even when training on mismatched non-Lombard visual speech, i.e., the increased clarity of the Lombard speech outweighed the impact of the mismatch. The paper presents two generally applicable conclusions: i) systems that are designed to operate in noise will benefit from being trained on well-matched Lombard speech data, ii) the results of speech recognition evaluations that employ artificial speech and noise mixing need to be treated with caution: they are overly-optimistic to the extent that they ignore a significant source of mismatch but at the same time overly-pessimistic in that they do not anticipate the potential increased intelligibility of the Lombard speaking style

Endemic, endangered and evolutionarily significant: cryptic lineages in Seychelles' frogs (Anura: Sooglossidae)

Cryptic diversity corresponding with island of origin has been previously reported in the endemic, geographically restricted sooglossid frogs of the Seychelles archipelago. The evolutionary pattern behind this has not been fully explored, and given current amphibian declines and the increased extinction risk faced by island species, we sought to identify evolutionarily significant units (ESUs) to address conservation concerns for these highly threatened anurans. We obtained genetic data for two mitochondrial (mtDNA) and four nuclear (nuDNA) genes from all known populations of sooglossid frog (on the islands of Mahé, Praslin and Silhouette) for phylogenetic analyses and to construct nuDNA haplotype networks. Bayesian and maximum likelihood analyses of mtDNA support the monophyly and molecular differentiation of populations in all species that occur on multiple islands. Haplotype networks using statistical parsimony revealed multiple high-frequency haplotypes shared between islands and taxa, in addition to numerous geographically distinct (island-specific) haplotypes for each species. We consider each island-specific population of sooglossid frog as an ESU and advise conservation managers to do likewise. Furthermore, our results identify each island lineage as a candidate species, evidence for which is supported by analyses of mtDNA based on Bayesian Poisson tree processes, and independent analyses of mtDNA and nuDNA using the multispecies coalescent. Our findings add to the growing understanding of the biogeography and hidden diversity within this globally important region

The impact of automatic exaggeration of the visual articulatory features of a talker on the intelligibility of spectrally distorted speech

Visual speech information plays a key role in supporting speech perception, especially when acoustic features are distorted or inaccessible. Recent research suggests that for spectrally distorted speech, the use of visual speech in auditory training improves not only subjects’ audiovisual speech recognition, but also their subsequent auditory-only speech recognition. Visual speech cues, however, can be affected by a number of facial visual signals that vary across talkers, such as lip emphasis and speaking style. In a previous study, we enhanced the visual speech videos used in perception training by automatically tracking and colouring a talker’s lips. This improved the subjects’ audiovisual and subsequent auditory speech recognition compared with those who were trained via unmodified videos or audio-only methods. In this paper, we report on two issues related to automatic exaggeration of the movement of the lips/ mouth area. First, we investigate subjects’ ability to adapt to the conflict between the articulation energy in the visual signals and the vocal effort in the acoustic signals (since the acoustic signals remained unexaggerated). Second, we have examined whether or not this visual exaggeration can improve the subjects’ performance of auditory and audiovisual speech recognition when used in perception training. To test this concept, we used spectrally distorted speech to train groups of listeners using four different training regimes: (1) audio only, (2) audiovisual, (3) audiovisual visually exaggerated, and (4) audiovisual visually exaggerated and lip-coloured. We used spectrally distorted speech (cochlear-implant-simulated speech) because the longer-term aim of our work is to employ these concepts in a training system for cochlear-implant (CI) users. The results suggest that after exposure to visually exaggerated speech, listeners had the ability to adapt alongside the conflicting audiovisual signals. In addition, subjects trained with enhanced visual cues (regimes 3 and 4) achieved better audiovisual recognition for a number of phoneme classes than those who were trained with unmodified visual speech (regime 2). There was no evidence of an improvement in the subsequent audio-only listening skills, however. The subjects’ adaptation to the conflicting audiovisual signals may have slowed down auditory perceptual learning, and impeded the ability of the visual speech to improve the training gains

Progressive refinement rendering of implicit surfaces

The visualisation of implicit surfaces can be an inefficient task when such surfaces are complex and highly detailed. Visualising a surface by first converting it to a polygon mesh may lead to an excessive polygon count. Visualising a surface by direct ray casting is often a slow procedure. In this paper we present a progressive refinement renderer for implicit surfaces that are Lipschitz continuous. The renderer first displays a low resolution estimate of what the final image is going to be and, as the computation progresses, increases the quality of this estimate at an interactive frame rate. This renderer provides a quick previewing facility that significantly reduces the design cycle of a new and complex implicit surface. The renderer is also capable of completing an image faster than a conventional implicit surface rendering algorithm based on ray casting

Bacteriophages to Control Campylobacter in Commercially Farmed Broiler Chickens, in Australia

© Copyright © 2020 The State of Queensland (through the Department Agriculture and Fisheries). This study describes the development and use of bacteriophage cocktails to control Campylobacter in broiler chickens, in a commercial setting, in Queensland Australia, following the birds from farm to the processing plant. The components of the bacteriophage cocktails were selected to be effective against the maximum number of Campylobacter jejuni and Campylobacter coli isolates encountered on SE Queensland farms. Farms were identified that had suitable Campylobacter target populations and phage were undetectable 1 week prior to the intended treatment. Cocktails of phages were administered at 47 days of age. Groups of study birds were slaughtered the following day, on-farm, at the end of flock transport to the plant, and at processing (approximately 28 h post-treatment). On Farm A, the phage treatment significantly reduced Campylobacter levels in the ceca at the farm in the range of 1–3 log10 CFU/g (p = 0.007), compared to mock treated controls. However, individual birds sampled on farm (1/10) or following transport (2/10) exhibited high cecal Campylobacter counts with low phage titers, suggesting that treatment periods > 24 h may be required to ensure phage replication for effective biocontrol in vivo. At the time of the trial the control birds in Farm B were phage positive despite having been negative one week earlier. There was no significant difference in the cecal Campylobacter counts between the treatment and control groups following treatment but a fall of 1.7 log10 CFU/g was observed from that determined from birds collected the previous week (p = 0.0004). Campylobacter isolates from both farms retained sensitivity to the treatment phages. These trials demonstrated bacteriophages sourced from Queensland farms have the potential to reduce intestinal Campylobacter levels in market ready broiler chickens

The Suaineadh Project : a stepping stone towards the deployment of large flexible structures in space

The Suaineadh project aims at testing the controlled deployment and stabilization of space web. The deployment system is based on a simple yet ingenious control of the centrifugal force that will pull each of the four daughters sections apart. The four daughters are attached onto the four corners of a square web, and will be released from their initial stowed configuration attached to a central hub. Enclosed in the central hub is a specifically designed spinning reaction wheel that controls the rotational speed with a closed loop control fed by measurements from an onboard inertial measurement sensor. Five other such sensors located within the web and central hub provide information on the surface curvature of the web, and progression of the deployment. Suaineadh is currently at an advanced stage of development: all the components are manufactured with the subsystems integrated and are presently awaiting full integration and testing. This paper will present the current status of the Suaineadh project and the results of the most recent set of tests. In particular, the paper will cover the overall mechanical design of the system, the electrical and sensor assemblies, the communication and power systems and the spinning wheel with its control system

Baby Pigs Have a Sweet Tooth!

Early gains are the cheapest. And you can get faster early gains by feeding a good pig starter. In this article, the others tell how pig starters can be made more palatable and also what should go into a good pig starter