99 research outputs found
Interpretable Timbre Synthesis using Variational Autoencoders Regularized on Timbre Descriptors
Controllable timbre synthesis has been a subject of research for several
decades, and deep neural networks have been the most successful in this area.
Deep generative models such as Variational Autoencoders (VAEs) have the ability
to generate a high-level representation of audio while providing a structured
latent space. Despite their advantages, the interpretability of these latent
spaces in terms of human perception is often limited. To address this
limitation and enhance the control over timbre generation, we propose a
regularized VAE-based latent space that incorporates timbre descriptors.
Moreover, we suggest a more concise representation of sound by utilizing its
harmonic content, in order to minimize the dimensionality of the latent space
Approaches for constant audio latency on Android
This paper discusses issues related to audio latency for realtime processing Android OS applications. We first introduce the problem, determining the difference between the concepts of low latency and constant latency. It is a well-known issue that programs written for this platform cannot implement low-latency audio. However, in some cases, while low latency is desirable, it is not crucial. In some of these cases, achieving a constant delay between control events and sound output is the necessary condition. The paper briefly outlines the audio architecture in the Android platform to tease out the difficulties. Following this, we proposed some approaches to deal with two basic situations, one where the audio callback system provided by the system software is isochronous, and one where it is not
Optimised procedures for the cryopreservation of different species of Heterorhabditis
It is demonstrated that the protocols developed for the cryopreservation of Heterorhabditis bacteriophora could be successfully applied to strains of the H. bacteriophora species complex and to members of the North West European species of Heterorhabditis. However the currently available protocols were not suitable for cryopreserving the Irish or the tropical Heterorhabditis species. Therefore, the postcryopreservation viabilities of Heterorhabditis species in response to preincubation in a range of cryoprotectants at varying concentrations and incubation times were determined. Species and strain specific differences in cryopreservation response were observed among Heterorhabditis isolates and optimal conditions were developed for the cryopreservation of Irish, NW European and tropical isolates of Heterorhabditis. These optimum conditions are described in this paper
Risk Assessment of E. coli Survival Up to the Grazing Exclusion Period After Dairy Slurry, Cattle Dung, and Biosolids Application to Grassland
peer-reviewedGrassland application of dairy slurry, cattle dung, and biosolids offers an opportunity to recycle valuable nutrients (N, P, and K), which may all introduce pathogens to the soil environment. Herein, a temporal risk assessment of the survival of Escherichia coli (E. coli) up to 40 days in line with the legislated grazing exclusion time points after application was examined across six scenarios: (1) soil and biosolids mixture, (2) biosolids amended soil, (3) dairy slurry application, (4) cattle dung on pasture, (5) comparison of scenario 2, 3, and 4, and (6) maximum legal vs. excess rate of application for scenario 2 and 3. The risk model input parameters were taken or derived from regressions within the literature and an uncertainty analysis (n = 1,000 trials for each scenario) was conducted. Scenario 1 results showed that E. coli survival was higher in the soil/biosolids mixture for higher biosolids portion, resulting in the highest 20 day value of residual E. coli concentration (i.e., C20, log10 CFU g−1 dw) of 1.0 in 100% biosolids or inoculated soil and the lowest C20 of 0.098 in 75/25 soil/biosolids ratio, respectively, in comparison to an average initial value of ~6.4 log10 CFU g−1 dw. The E. coli survival across scenario 2, 3, and 4 showed that the C20 value of biosolids (0.57 log10 CFU g−1 dw) and dairy slurry (0.74 log10 CFU ml−1) was 2.9–3.7 times smaller than that of cattle dung (2.12 log10 CFU g−1 dw). The C20 values of biosolids and dairy slurry associated with legal and excess application rates ranged from 1.14 to 1.71 log10 CFU ha−1, which is a significant reduction from the initial concentration range (12.99 to 14.83 log10 CFU ha−1). The E. coli survival in un-amended soil was linear with a very low decay rate resulting in a higher C20 value than that of biosolids or dairy slurry. The risk assessment and uncertainly analysis showed that the residual concentrations in biosolids/dairy slurry applied soil after 20 days would be 45–57% lower than that of the background soil E. coli concentration. This means the current practice of grazing exclusion times is safe to reduce the risk of E. coli transmission into the soil environment.This publication has emanated from research funded by the EU FP7 Environment theme–Grant no. 265269 Marketable sludge derivatives from a highly integrated wastewater treatment plant (END-O-SLUDG)
Beneath the Top End: a regional assessment of submerged archaeological potential in the Northern Territory, Australia
Regional-scale assessments have proven to be invaluable frameworks for research, public engagement and management of submerged archaeological landscapes. Regional-scale approaches have been implemented internationally through a variety of academic or strategic studies. Such studies represent a much-needed next step towards subregional and site-level prospection to support management, engagement and mitigation of the impacts of offshore development. However, these regional studies are largely absent in Australia. In this article, we build on the recent discovery of submerged archaeological sites in Western Australia and produce a novel regional-scale assessment of submerged archaeological and cultural landscape potential in the coastal and island regions of the Northern Territory. This area is of special significance in the peopling of Australia, containing some of the oldest dated archaeological evidence. We collate and synthesise regional data related to sea-level change, ethnography (e.g. oral traditions), geomorphology, and archaeology, also taking account of logistics and existing data availability to identify prospective areas for further study. We highlight the need for a coordinated national program of regional baseline studies to address a legacy of under-representation of submerged landscapes and provide vital baseline data for a wide spectrum of stakeholders, including researchers, policy makers, environmental and heritage managers, developers and Traditional Owners
The effect of day of emergence from the insect cadaver on the behaviour and environmental tolerances of infective juveniles of the entomopathogenic nematode Heterorhabditis Megidis (Strain UK211)
Infective juveniles (Us) of entomopathogenic nematodes (EPNs) are obligate parasites of insect larvae. Inside the host they develop into sexually mature adult stages and complete their life cycle. Two or 3 adult nematode generations can occur in the insect host. The increase in nematode population density in the insect cadaver, together with limiting nutrient conditions, result in the formation of IJs. These IJs emerge into the soil to search for a new host. It typically takes 7-8 days for all Us to emerge from a parasitized insect. We have investigated the effect of the day of emergence of Us from insect cadavers on the environmental tolerance and behavior of the EPN Heterorhabditis megidis strain UK211. The Us that emerge early display good initial host-finding ability and increased temperature tolerance but disperse poorly and have poor tolerance to desiccation. Conversely, the IJs that emerge later display poor initial host-finding ability and poor temperature tolerance but they disperse well and possess increased desiccation tolerance. These phenotypic differences are likely to facilitate early-emerging Us in locating and infecting hosts in the vicinity of the cadaver, whereas IJs that emerge late are adapted to disperse away from their natal cadaver. We hypothesize that adaptive phenotypic plasticity rather than allelic variability may provide the genetic basis for the different physiological and behavioral phenotypes of the early- and late-emerging IJs
Stratus Ocean Reference Station (20˚S, 85˚W) mooring recovery and deployment cruise STRATUS 8 R/V Ronald H. Brown cruise 07-09 October 9, 2007–November 6, 2007
The Ocean Reference Station at 20°S, 85°W under the stratus clouds west of northern Chile is
being maintained to provide ongoing climate-quality records of surface meteorology (air-sea
fluxes of heat, freshwater, and momentum), and of upper ocean temperature, salinity, and
velocity variability. The Stratus Ocean Reference Station (ORS Stratus) is supported by the
National Oceanic and Atmospheric Administration’s (NOAA) Climate Observation Program. It
is recovered and redeployed annually, with cruises between October and December.
During the October 2007 cruise on the NOAA ship Ronald H. Brown to the ORS Stratus site, the
primary activities were recovery of the Stratus 7 WHOI surface mooring that had been deployed
in October 2006, deployment of a new (Stratus 8) WHOI surface mooring at that site; in-situ
calibration of the buoy meteorological sensors by comparison with instrumentation put on board
the ship by staff of the NOAA Earth System Research Laboratory (ESRL); and observations of
the stratus clouds and lower atmosphere by NOAA ESRL. Meteorological sensors on a buoy for
the Pacific tsunami warning system were also serviced, in collaboration with the Hydrographic
and Oceanographic Service of the Chilean Navy (SHOA). The DART (Deep-Ocean Assessment
and Reporting of Tsunami) carries IMET sensors and subsurface oceanographic instruments. A
new DART II buoy was deployed north of the STRATUS buoy, by personnel from the National
Data Buoy Center (NDBC) Argo floats and drifters were launched, and CTD casts carried out
during the cruise.
The ORS Stratus buoys are equipped with two Improved Meteorological (IMET) systems, which
provide surface wind speed and direction, air temperature, relative humidity, barometric
pressure, incoming shortwave radiation, incoming longwave radiation, precipitation rate, and sea
surface temperature. Additionally, the Stratus 8 buoy received a partial pressure of CO2 detector
from the Pacific Marine Environmental Laboratory (PMEL). IMET data are made available in
near real time using satellite telemetry. The mooring line carries instruments to measure ocean
salinity, temperature, and currents.
The ESRL instrumentation used during the 2007 cruise included cloud radar, radiosonde
balloons, and sensors for mean and turbulent surface meteorology. Finally, the cruise hosted a
teacher participating in NOAA’s Teacher at Sea Program.Funding was provided by the National Oceanic and Atmospheric Administration
under Grant No. NA17RJ1223 for the Cooperative Institute for Climate and Ocean Research (CICOR)
Aboriginal artefacts on the continental shelf reveal ancient drowned cultural landscapes in northwest Australia
This article reports Australia’s first confirmed ancient underwater archaeological sites from the continental shelf, located off the Murujuga coastline in north-western Australia. Details on two underwater sites are reported: Cape Bruguieres, comprising > 260 recorded lithic artefacts at depths down to −2.4 m below sea level, and Flying Foam Passage where the find spot is associated with a submerged freshwater spring at −14 m. The sites were discovered through a purposeful research strategy designed to identify underwater targets, using an iterative process incorporating a variety of aerial and underwater remote sensing techniques and diver investigation within a predictive framework to map the submerged landscape within a depth range of 0–20 m. The condition and context of the lithic artefacts are analysed in order to unravel their depositional and taphonomic history and to corroborate their in situ position on a pre-inundation land surface, taking account of known geomorphological and climatic processes including cyclone activity that could have caused displacement and transportation from adjacent coasts. Geomorphological data and radiometric dates establish the chronological limits of the sites and demonstrate that they cannot be later than 7000 cal BP and 8500 cal BP respectively, based on the dates when they were finally submerged by sea-level rise. Comparison of underwater and onshore lithic assemblages shows differences that are consistent with this chronological interpretation. This article sets a foundation for the research strategies and technologies needed to identify archaeological targets at greater depth on the Australian continental shelf and elsewhere, building on the results presented. Emphasis is also placed on the need for legislation to better protect and manage underwater cultural heritage on the 2 million square kilometres of drowned landscapes that were once available for occupation in Australia, and where a major part of its human history must lie waiting to be discovered
Stone artefacts on the seabed at a submerged freshwater spring confirm a drowned cultural landscape in Murujuga, Western Australia
We report the discovery and identification of five ancient stone artefacts associated with a submerged freshwater spring at the underwater archaeological site WH1 in Murujuga (Dampier Archipelago), Western Australia. A limiting date applied to the site based on timing of inundation suggests it was occupied in the Late Pleistocene or Early Holocene. The site is situated well below the intertidal zone having been recorded at 14 m depth in Flying Foam Passage. This discovery highlights the high potential of these submerged springs as archaeological survey targets. We discuss results of a recent survey that expands the number of confirmed artefacts located at WH1 and the geomorphological context in a large calcareous depression associated with a freshwater source. This study demonstrates how submerged landscape research using a suite of technologies can reveal archaeological assemblages in this tropical geomorphological environment, and that adapted techniques could be applied to other tropical conditions such as mangrove coasts, large deltaic plains, or reef-building environments. There are likely thousands of drowned archaeological sites on the continental shelf of the tropics, extending from the intertidal zone to the lowest point of the culturally occupied landmass, at approximately 130 m below modern sea level
A strategy for assessing continuity in terrestrial and maritime landscapes from Murujuga (Dampier Archipelago), North West Shelf, Australia
Over the last 20,000 years one-third of the continental land mass of Australia, or 2.12 million km2, has been drowned by postglacial sea-level rise. Much of this drowned territory is thought to have been occupied by humans and where archaeological remains have survived inundation, they can be investigated by underwater and airborne remote sensing, survey and ground-truthing. This study of the Dampier Archipelago of NW Australia is contextualised by a review of the current state of the art of underwater prehistory. In the absence of known sites, we propose terrestrial analogy as a predictive tool for targeting submerged archaeological sites. Geological and topographic contexts are important for assessing preservation potential as is identifying landforms and features around which people may have focused their occupation. Analysis of over 2,500 known archaeological sites from the extraordinarily rich Dampier Archipelago reveals that the vast majority are rock art sites but these are interspersed by a significant number of artefact scatters, myriad stone structures, shell middens and quarry and reduction areas. The majority of these sites are focused on coastal and interior valleys, associated uplands and coastal embayments. While over two-thirds of sites occur on granophyre and basalt substrates, the others are located on quaternary sediments. Regional research on nearby continental islands shows that use of these environments can be expected to pre-date sea level rise. The most likely submerged sites include (i) compacted middens associated with rock pools and estuarine features; (ii) stone structures with associated midden on limestone pavements or with granophyre and basalt boulder fields; (iii) buried midden and other occupation deposits on protected sand sheets; (iv) quarry outcrops, extraction pits and associated reduction debris in areas of fine-grained granophyre and basalt; and (v) midden in consolidated calcarenite shoreline contexts to the north and west of the volcanic suites of the Dampier Archipelago
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