447 research outputs found
Spectral density affects the intelligibility of tone-vocoded speech: Implications for cochlear implant simulations
For small numbers of channels, tone vocoders using low envelope cutoff frequencies are less intelligible than noise vocoders, even though the noise carriers introduce random fluctuations into the crucial envelope information. Here it is shown that using tone carriers with a denser spectrum improves performance considerably over typical tone vocoders, at least equalling,
and often surpassing, the performance possible with noise vocoders. In short, the spectral sparseness of tone vocoded sounds for low channel numbers, separate from the degradations introduced by using only a small number of channels, is an important limitation on the
intelligibility of tone-vocoded speech
Utilizing synthetic training data for the supervised classification of rat ultrasonic vocalizations
Murine rodents generate ultrasonic vocalizations (USVs) with frequencies that
extend to around 120kHz. These calls are important in social behaviour, and so
their analysis can provide insights into the function of vocal communication,
and its dysfunction. The manual identification of USVs, and subsequent
classification into different subcategories is time consuming. Although machine
learning approaches for identification and classification can lead to enormous
efficiency gains, the time and effort required to generate training data can be
high, and the accuracy of current approaches can be problematic. Here we
compare the detection and classification performance of a trained human against
two convolutional neural networks (CNNs), DeepSqueak and VocalMat, on audio
containing rat USVs. Furthermore, we test the effect of inserting synthetic
USVs into the training data of the VocalMat CNN as a means of reducing the
workload associated with generating a training set. Our results indicate that
VocalMat outperformed the DeepSqueak CNN on measures of call identification,
and classification. Additionally, we found that the augmentation of training
data with synthetic images resulted in a further improvement in accuracy, such
that it was sufficiently close to human performance to allow for the use of
this software in laboratory conditions.Comment: 25 pages, 5 main figures, 2 table
Infrared and Raman screening of seized novel psychoactive substances:a large scale study of >200 samples
The potential of IR absorption and Raman spectroscopy for rapid identification of novel psychoactive sub- stances (NPS) has been tested using a set of 221 unsorted seized samples suspected of containing NPS. Both IR and Raman spectra showed large variation between the different sub-classifications of NPS and smaller, but still distinguishable, differences between closely related compounds within the same class. In initial tests, screening the samples using spectral searching against a limited reference library allowed only 41% of the samples to be fully identified. The limiting factor in the identification was the large number of active compounds in the seized samples for which no reference vibrational data were available in the libraries rather than poor spectral quality. Therefore, when 33 of these compounds were independently identified by NMR and mass spectrometry and their spectra used to extend the libraries, the percentage of samples identified by IR and Raman screening alone increased to 76%, with only 7% of samples having no identifiable constituents. This study, which is the largest of its type ever carried out, therefore demon- strates that this approach of detecting non-matching samples and then identifying them using standard analytical methods has considerable potential in NPS screening since it allows rapid identification of the constituents of the majority of street quality samples. Only one complete feedback cycle was carried out in this study but there is clearly the potential to carry out continuous identification/updating when this system is used in operational settings
Hippocampal sequencing mechanisms are disrupted in a maternal immune activation model of schizophrenia risk
Episodic memory requires information to be stored and recalled in sequential order, and these processes are disrupted in schizophrenia. Hippocampal phase precession and theta sequences are thought to provide a biological mechanism for sequential ordering of experience at timescales suitable for plasticity. These phenomena have not previously been examined in any models of schizophrenia risk. Here, we examine these phenomena in a maternal immune activation (MIA) rodent model. We show that while individual pyramidal cells in the CA1 region continue to precess normally in MIA animals, the starting phase of precession as an animal enters a new place field is considerably more variable in MIA animals than in controls. A critical consequence of this change is a disorganization of the ordered representation of experience via theta sequences. These results provide the first evidence of a biological-level mechanism that, if it occurs in schizophrenia, may explain aspects of disorganized sequential processing that contribute to the cognitive symptoms of the disorder
The Pine Needle, February 1947
Libraries and archives collect materials from different cultures and time periods to preserve and make available the historical record. As a result, materials such as those presented here may reflect sexist, misogynistic, abusive, racist, or discriminatory attitudes or actions that some may find disturbing, harmful, or difficult to view.
Both a humor and literary magazine, The Pine Needle was a University of Maine student-produced periodical that began publication in the fall of 1946, the first post-World War II semester that saw GIs returning to campus.
The Needle reflected an edginess and rebellion not found in previous UMaine student publications. While past student publications relied on euphemisms for alcohol and dating on campus, The Needle overtly sexualized co-eds and discussed the use of drugs, tobacco, and alcohol by students.
Cover art for this issue is an unsigned pen-and-ink illustration produced by a member of The Needle\u27s art staff. It depicts the five members of the editorial staff gathered around a wood coffin labeled, The Needle.
Included in this issue is a piece about former History Professor C. Dewitt Hardy II\u27s (1911-1992), term paper assignment entitled, Social Problems in My Home Town. The work mentions the birth of Hardy\u27s son and future artist, Clarion Dewitt Hardy III (1940-2017)
The lncRNA landscape of breast cancer reveals a role for DSCAM-AS1 in breast cancer progression.
Molecular classification of cancers into subtypes has resulted in an advance in our understanding of tumour biology and treatment response across multiple tumour types. However, to date, cancer profiling has largely focused on protein-coding genes, which comprise <1% of the genome. Here we leverage a compendium of 58,648 long noncoding RNAs (lncRNAs) to subtype 947 breast cancer samples. We show that lncRNA-based profiling categorizes breast tumours by their known molecular subtypes in breast cancer. We identify a cohort of breast cancer-associated and oestrogen-regulated lncRNAs, and investigate the role of the top prioritized oestrogen receptor (ER)-regulated lncRNA, DSCAM-AS1. We demonstrate that DSCAM-AS1 mediates tumour progression and tamoxifen resistance and identify hnRNPL as an interacting protein involved in the mechanism of DSCAM-AS1 action. By highlighting the role of DSCAM-AS1 in breast cancer biology and treatment resistance, this study provides insight into the potential clinical implications of lncRNAs in breast cancer
Flocculation onset in Saccharomyces cerevisiae: effect of ethanol, heat and osmotic stress
Aims: To examine the effect of different stress conditions on the onset of flocculation
in an ale-brewing strain, Saccharomyces cerevisiae NCYC 1195.
Methods and Results: Flocculation was evaluated using the method of Soares,
E.V. and Vroman, A. [Journal of Applied Microbiology (2003) 95, 325]; plasma
membrane integrity was accessed using propidium iodide and the staining of
the yeast cell wall was performed using calcofluor white M2R. Cells in exponential
phase of growth were subjected to different stress conditions. The addition
of 1%, 3% and 5% (v/v) ethanol, 1% and 3% (v/v) isopropanol or a brief heat shock (52ºC, 5 min), did not induce an early flocculation phenotype when compared with control cells. The addition of 10% (v/v) ethanol, a continuous mild heat-stress (37ºC) or an osmotic stress (0.5 or 1 mol l-1 of NaCl) did not induce a flocculent phenotype.
Conclusions: Flocculation seems not to be induced as a response to different
chemical (ethanol and isopropanol) and physical (heat and osmotic) stress conditions.
Conversely, osmotic and ethanol [10% (v/v)] stress, as well as a continuous mild heat shock (37ºC), have a negative impact on the phenotype expression of flocculation.
Significance and Impact of the Study: The findings reported here contribute to
the elucidation of the control of yeast flocculation. This information might be
useful to the brewing industry, as the time when the onset of flocculation
occurs can determine the fermentation performance and the beer quality, as
well as in other biotechnological industries where flocculation can be used as a
cell separation process.ERASMUS; ISEP (Portugal)
An overview of the Jordanian oil shale: its chemical and geologic characteristics, exploration, reserves and feasibility for oil and cement production
Abstract
Oil shale is the most abundant fossil energy resource discovered in Jordan, ranking third after the USA and Brazil in terms of oil shale reserves. This asset is considered to be Jordan's most extensive domestic fossil-fuel source. The identified reserves of this oil shale are huge and sufficient to satisfy the national energy needs for hundreds of years. Numerous geologic studies have shown that the country contains several oil shale deposits. These deposits are regarded as the richest in organic bituminous marl and limestone that occur at shallow depth. Jordanian oil shale is generally of a good quality, with relatively low ash and moisture contents, a gross calorific value of 7.5 MJ/kg, and an oil yield of 8 to 12%. The spent shale has residual carbon content that may be burned to produce further energy, and ash that can be used for cement and building materials. The current study summarizes the results of the former feasibility studies and discuses the scope of future usage of Jordanian oil shale. The value of this oil shale and its associated products is highlighted herein
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