Speech Separation Using Partially Asynchronous Microphone Arrays Without Resampling

We consider the problem of separating speech sources captured by multiple spatially separated devices, each of which has multiple microphones and samples its signals at a slightly different rate. Most asynchronous array processing methods rely on sample rate offset estimation and resampling, but these offsets can be difficult to estimate if the sources or microphones are moving. We propose a source separation method that does not require offset estimation or signal resampling. Instead, we divide the distributed array into several synchronous subarrays. All arrays are used jointly to estimate the time-varying signal statistics, and those statistics are used to design separate time-varying spatial filters in each array. We demonstrate the method for speech mixtures recorded on both stationary and moving microphone arrays.Comment: To appear at the International Workshop on Acoustic Signal Enhancement (IWAENC 2018

Acoustic Impulse Responses for Wearable Audio Devices

We present an open-access dataset of over 8000 acoustic impulse from 160 microphones spread across the body and affixed to wearable accessories. The data can be used to evaluate audio capture and array processing systems using wearable devices such as hearing aids, headphones, eyeglasses, jewelry, and clothing. We analyze the acoustic transfer functions of different parts of the body, measure the effects of clothing worn over microphones, compare measurements from a live human subject to those from a mannequin, and simulate the noise-reduction performance of several beamformers. The results suggest that arrays of microphones spread across the body are more effective than those confined to a single device.Comment: To appear at ICASSP 201

Geological features within the Big Indian Lake pluton, Hants County, Nova Scotia: evidence of igneous layering from recent diamond drilling

This paper describes geological features observed in diamond drill core recovered from three holes in the Big Indian Lake pluton near the eastern margin of the South Mountain Batholith. The pluton is comprised of four texturally variable granitic facies (order of decreasing abundance): (1) megacrystic to equigranular monzogranite and leuco-monzogranite, (2) porphyritic biotite monzogranite, (3) equigranular leucomonzogranite, and (4) microgranitc. Evidence of igneous layering observed in drill core includes: (1) the presence of a cumulate-like aggregate of plagioclase, (2) centimetre-thick layers modally enriched in biotite and apatite, and (3) gradational contacts between granitic rock-types. The plagioclase aggregate contains SO to 90% zoned and generally equidimensional plagioclase crystals which commonly have mutually interfering grain boundaries and a poikilitic texture characterized by abundant biotite inclusions. Contacts of the plagioclase aggregate with other facies of the pluton are generally gradational, and marked by a progressive increase in biotite and decrease in euhedral plagioclase crystals. The amount of plagioclase-rich aggregate decreases with depth in the drill core, and granodiorite and biotite monzogranite become more abundant. They grade into predominately leucomonzogranite and microgranite at depth. The microgranite is typically of syenogranite composition and closely associated with several types of alteration and mineralization. The common occurrence of pegmatite within the microgranite at boundaries with equigranular leucomonzogranite suggests that the microgranitc crystallized from a highly fractionated, water-saturated liquid. The microgranite may represent a texturally and mineralogically modified leucomonzogranite rather than a primary magmalic product. The occurrence of what appears to be primary magmatic layering in the Big Indian Lake pluton appears to confirm the relevance of applying fractional crystallization models to the South Mountain Batholith. RÉSUMÉ Cet article décrit les caractéristiques géologiques de trois forages dans le pluton du lac Big Indian, près de la bordure est du balholite du mont South. Lc pluton est composé de quatre faciès granitiques de diverses textures (en ordre d'abondanée déeroissante): (1) des monzogranites et leucomonzogranites à mégacristaux ou équigranulaires, (2) des monzonites porphyriques à biotite, (3) des leucomonzogranites équigranulaires et (4) des microgranites. Les indications de litage magmatique observers en forage sont: (1) la présence d'un aggrégat de plagioclase semblable à un cumulat, (2) des lits centimétriques enrichis en biotite et en apatite et (3) des contacts graduels entre les types de granite. L’aggrégat de plagioclase contient de 50 à 90% de cristaux de plagioclase zonés et généralement trapus qui ont communémwnt des contacts enginés et une texture poecilitique avec d'abondantes inclusions de biotite. Les contacts de l'aggrégate plagioclase avec les autres faciès du pluton sont gendralement graduels el sont soulignés par un enrichissement progressif en biotite et un appauvrissement en cristaux de plagioclase euédriques. La proportion d'aggrégat riche en plagioclase décroit avec la profondeur tandis que la granodiorite et le monzogranite à biotite deviennent plus abondants. Le microgranitc a typiquemenl unc composition de syénogranite et est intimement associé à de l'altération et de la minéralisation. L'abondance de pegmatite au sein du microgranite en contact avec les leucomonzogranites équigranulaires suggère que le microgranite à cristallisé à partir d'un magma très différencié et saturé en eau. Le microgranite pourrait représenter un leucomonzogranite dont la texture et la minéralogie ont été modifiers plutôt qu'un produit magmatique primaire. Le présence de ce qui est apparemment un litage magmatique primaire dans le pluton du lac Big Indian semble confirmer la pertinence des modèles de cristallisation fractionnée pour le batholite du mont South. [Traduit par le journal

Zebrafish Model of MLL-Rearranged Acute Myeloid Leukemia

Background: Acute myeloid leukemia (AML) is the second most common type of leukemia. Standard treatment includes chemotherapy as well as stem cell transplantation, but for aging patients and those with impaired immune function these rigorous therapies are not always possible. Furthermore, AML patients harboring a chromosomal rearrangement involving Multiple Lineage Leukemia (MLL) exhibit far worse prognoses than patients without. Given these circumstances new therapies must be developed. Methods: Danio rerio (zebrafish) has emerged as a powerful model organism for investigating human blood malignancies due to the conservation of hematopoiesis between humans and zebrafish. We developed a transient transgenic model exhibiting AML characteristics by microinjecting single-cell zebrafish embryos with a tissue specific MLL-ENL expression construct. Results: We found that the expression of MLL-ENL induced a clustered expansion of MLL+ and pu.1+ myeloid cells on the yolk sac at 48 and 72 hours post fertilization (hpf). To characterize our transient AML model, we treated MLL-ENL expressing embryos with either one of or a combination of two drugs that are currently being used in human AML drug trials, Venetoclax and Flavopiridol. We found that treatment with either drug reduced the myeloid expansion induced by the expression of MLL-ENL, and that co-treatment reduced the observed myeloid expansion even further. Conclusions: Although further analysis is required, these data suggest that we successfully developed a transient transgenic AML model in zebrafish. Furthermore, these data suggest that Venetoclax and Flavopiridol co-treatment could yield better outcomes for AML patients than treatment with either drug individually.https://scholarscompass.vcu.edu/gradposters/1112/thumbnail.jp

A cost-effectiveness analysis of tactical satellites, high-altitude long-endurance airships, and high and medium altitude unmanned aerial systems for ISR and communication missions

Before 1991, the United States military's demand for additional communications bandwidth and timely intelligence was rising rapidly. Since then, with the advent of the Global War on Terrorism, it has increased substantially. To address this growing need, the Department of Defense has focused its acquisition and procurement efforts on obtaining new communications and intelligence, surveillance, and reconnaissance (ISR) platforms that can help lessen shortfalls and possibly exploit new, untapped resources. Recently, there has been an increasing focus on new technology, such as tactical satellites or high-altitude long-endurance airships, as a way to increase communications and intelligence collection capacities. Likewise, advances in the capabilities of medium-altitude and high-altitude unmanned aerial systems have resulted in a more prominent role for them on today's battlefield. Each of these vehicles has a unique niche in today's military, but the increasing capabilities of each are beginning to create some overlap in their uses. This study will conduct a cost-effectiveness analysis on these systems for use as a persistent communications and ISR platform. In particular, it will measure the effectiveness of each for comparison, and will offer possibilities to increase the overall effective use of the three together to maximize performance and cost.http://archive.org/details/acosteffectivene109453934US Army (USA) author.Approved for public release; distribution is unlimited