14,402 research outputs found
Amide proton transfer MR imaging in peritoneal metastasis evaluation
Theme for ISMRM 21st Annual Meeting & Exhibition: Discovery, Innovation & Application - Advancing MR for Improved HealthTheme for SMRT 22nd Annual Meeting: Changing the World through MR Education and InnovationPURPOSE: Cytoreductive surgery has emerged as a neoadjuvant treatment to intraperitoneal and hyperthermic chemotherapy, which are potentially effective in controlling local disease. Therefore evaluation of peritoneal dissemination is essential for early diagnosis and treatment planning. MRI has been used in peritoneal metastasis imaging, with gadolinium-enhanced MRI sensitive in depicting peritoneal disseminations of small volume. CEST MRI is a novel molecular imaging technique that is able to assess the concentration of mobile proteins and peptides indirectly through bulk water signals. CEST MRI using amide protons as contrast agent, term…published_or_final_versio
Hazardous Apoptotic Effects of 2-Bromopropane on Maturation of Mouse Oocytes, Fertilization, and Fetal Development
2-Bromopropane (2-BP) is used as an alternative to ozone-depleting cleaning solvents. Previously, we reported that 2-BP has cytotoxic effects on mouse blastocysts and is associated with defects in subsequent development. Here, we further investigate the effects of 2-BP on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, 2-BP induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with 2-BP during in vitro maturation (IVM) resulted in increased resorption of postimplantation embryos and decreased fetal weights. Experiments with a mouse model disclosed that consumption of drinking water containing 20 μM 2-BP led to decreased oocyte maturation in vivo and fertilization in vitro, as well as impairment of early embryonic development. Interestingly, pretreatment with a caspase-3-specific inhibitor effectively prevented 2-BP-triggered hazardous effects, suggesting that embryonic impairment by 2-BP occurs via a caspase-dependent apoptotic process. A study using embryonic stem cells as the assay model conclusively demonstrated that 2-BP induces cell death processes through apoptosis and not necrosis, and inhibits early embryo development in mouse embryonic stem cells. These results collectively confirm the hazardous effects of 2-BP on embryos derived from pretreated oocytes
Towards a shared ontology: a generic classification of cognitive processes in conceptual design
Towards addressing ontological issues in design cognition research, this paper presents the first generic classification of cognitive processes investigated in protocol studies on conceptual design cognition. The classification is based on a systematic review of 47 studies published over the past 30 years. Three viewpoints on the nature of design cognition are outlined (search, exploration and design activities), highlighting considerable differences in the concepts and terminology applied to describe cognition. To provide a more unified view of the cognitive processes fundamentally under study, we map specific descriptions of cognitive processes provided in protocol studies to more generic, established definitions in the cognitive psychology literature. This reveals a set of 6 categories of cognitive process that appear to be commonly studied and are therefore likely to be prevalent in conceptual design: (1) long-term memory; (2) semantic processing; (3) visual perception; (4) mental imagery processing; (5) creative output production and (6) executive functions. The categories and their constituent processes are formalised in the generic classification. The classification provides the basis for a generic, shared ontology of cognitive processes in design that is conceptually and terminologically consistent with the ontology of cognitive psychology and neuroscience. In addition, the work highlights 6 key avenues for future empirical research: (1) the role of episodic and semantic memory; (2) consistent definitions of semantic processes; (3) the role of sketching from alternative theoretical perspectives on perception and mental imagery; (4) the role of working memory; (5) the meaning and nature of synthesis and (6) unidentified cognitive processes implicated in conceptual design elsewhere in the literature
PAS: Partial Additive Speech Data Augmentation Method for Noise Robust Speaker Verification
Background noise reduces speech intelligibility and quality, making speaker
verification (SV) in noisy environments a challenging task. To improve the
noise robustness of SV systems, additive noise data augmentation method has
been commonly used. In this paper, we propose a new additive noise method,
partial additive speech (PAS), which aims to train SV systems to be less
affected by noisy environments. The experimental results demonstrate that PAS
outperforms traditional additive noise in terms of equal error rates (EER),
with relative improvements of 4.64% and 5.01% observed in SE-ResNet34 and
ECAPA-TDNN. We also show the effectiveness of proposed method by analyzing
attention modules and visualizing speaker embeddings.Comment: 5 pages, 2 figures, 1 table, accepted to CKAIA2023 as a conference
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Aberrant oligodendroglial-vascular interactions disrupt the blood-brain barrier, triggering CNS inflammation.
Disruption of the blood-brain barrier (BBB) is critical to initiation and perpetuation of disease in multiple sclerosis (MS). We report an interaction between oligodendroglia and vasculature in MS that distinguishes human white matter injury from normal rodent demyelinating injury. We find perivascular clustering of oligodendrocyte precursor cells (OPCs) in certain active MS lesions, representing an inability to properly detach from vessels following perivascular migration. Perivascular OPCs can themselves disrupt the BBB, interfering with astrocyte endfeet and endothelial tight junction integrity, resulting in altered vascular permeability and an associated CNS inflammation. Aberrant Wnt tone in OPCs mediates their dysfunctional vascular detachment and also leads to OPC secretion of Wif1, which interferes with Wnt ligand function on endothelial tight junction integrity. Evidence for this defective oligodendroglial-vascular interaction in MS suggests that aberrant OPC perivascular migration not only impairs their lesion recruitment but can also act as a disease perpetuator via disruption of the BBB
Resveratrol Protects against 2-Bromopropane-Induced Apoptosis and Disruption of Embryonic Development in Blastocysts
2-Bromopropane (2-BP) is used as an alternative to ozone-depleting cleaning solvents. Previously, we reported that 2-BP has cytotoxic effects on mouse blastocysts and is associated with defects in subsequent development. In the present work, we show that 2-BP induces apoptosis in the inner cell mass of mouse blastocysts, and inhibits cell proliferation. Both effects are suppressed by resveratrol, a grape-derived phytoalexin with known antioxidant and anti-inflammatory properties. 2-BP-treated blastocysts displayed lower levels of implantation (compared to controls) when plated on culture dishes in vitro, and a reduced ability to proceed to later stages of embryonic development. Pretreatment with resveratrol prevented 2-BP-induced disruption of embryonic development, both in vitro and in vivo. Further investigation of these processes revealed that 2-BP directly promotes ROS generation, loss of mitochondrial membrane potential (MMP), and activation of caspase-3, whereas resveratrol effectively blocks 2-BP-induced ROS production and the accompanying apoptotic biochemical changes. Our results collectively imply that 2-BP triggers the mitochondrion-dependent apoptotic pathway via ROS generation, and the antioxidant activity of resveratrol prevents 2-BP-induced toxicity
Complete response to FOLFOX4 therapy in a patient with advanced urothelial cancer: a case report
No standard has been established for salvage therapy in gemcitabine refractory advanced urothelial cancer. We report the complete response to FOLFOX4 therapy of a metastatic urothelial cancer patient, for whom adjuvant gemcitabine plus cisplatin combination chemotherapy had failed. A 54-year-old male patient with urothelial cancer (transitional cell carcinoma) in the right kidney underwent three rounds of adjuvant gemcitabine-cisplatin chemotherapy after extensive radical nephrectomy. However, he had new liver, lung metastases and synchronous two separate primary colon cancer. The lung metastasis lesion was confirmed as a metastatic urothelial cancer via percutaneous transthoracic needle biopsy (PTNB). Liver and lung metastasis lesions disappeared after the 4th cycle of FOLFOX4 chemotherapy. In addition, colon cancer also disappeared after the 8th cycle of FOLFOX4 chemotherapy. The patient was still showing a complete response after 4 months. Clinical trials using the FOLFOX regimen as salvage therapy for gemcitabine-refractory advanced urothelial cancer are warranted
Convolution channel separation and frequency sub-bands aggregation for music genre classification
In music, short-term features such as pitch and tempo constitute long-term
semantic features such as melody and narrative. A music genre classification
(MGC) system should be able to analyze these features. In this research, we
propose a novel framework that can extract and aggregate both short- and
long-term features hierarchically. Our framework is based on ECAPA-TDNN, where
all the layers that extract short-term features are affected by the layers that
extract long-term features because of the back-propagation training. To prevent
the distortion of short-term features, we devised the convolution channel
separation technique that separates short-term features from long-term feature
extraction paths. To extract more diverse features from our framework, we
incorporated the frequency sub-bands aggregation method, which divides the
input spectrogram along frequency bandwidths and processes each segment. We
evaluated our framework using the Melon Playlist dataset which is a large-scale
dataset containing 600 times more data than GTZAN which is a widely used
dataset in MGC studies. As the result, our framework achieved 70.4% accuracy,
which was improved by 16.9% compared to a conventional framework
Integrated Parameter-Efficient Tuning for General-Purpose Audio Models
The advent of hyper-scale and general-purpose pre-trained models is shifting
the paradigm of building task-specific models for target tasks. In the field of
audio research, task-agnostic pre-trained models with high transferability and
adaptability have achieved state-of-the-art performances through fine-tuning
for downstream tasks. Nevertheless, re-training all the parameters of these
massive models entails an enormous amount of time and cost, along with a huge
carbon footprint. To overcome these limitations, the present study explores and
applies efficient transfer learning methods in the audio domain. We also
propose an integrated parameter-efficient tuning (IPET) framework by
aggregating the embedding prompt (a prompt-based learning approach), and the
adapter (an effective transfer learning method). We demonstrate the efficacy of
the proposed framework using two backbone pre-trained audio models with
different characteristics: the audio spectrogram transformer and wav2vec 2.0.
The proposed IPET framework exhibits remarkable performance compared to
fine-tuning method with fewer trainable parameters in four downstream tasks:
sound event classification, music genre classification, keyword spotting, and
speaker verification. Furthermore, the authors identify and analyze the
shortcomings of the IPET framework, providing lessons and research directions
for parameter efficient tuning in the audio domain.Comment: 5 pages, 3 figures, submit to ICASSP202
One-Step Knowledge Distillation and Fine-Tuning in Using Large Pre-Trained Self-Supervised Learning Models for Speaker Verification
The application of speech self-supervised learning (SSL) models has achieved
remarkable performance in speaker verification (SV). However, there is a
computational cost hurdle in employing them, which makes development and
deployment difficult. Several studies have simply compressed SSL models through
knowledge distillation (KD) without considering the target task. Consequently,
these methods could not extract SV-tailored features. This paper suggests
One-Step Knowledge Distillation and Fine-Tuning (OS-KDFT), which incorporates
KD and fine-tuning (FT). We optimize a student model for SV during KD training
to avert the distillation of inappropriate information for the SV. OS-KDFT
could downsize Wav2Vec 2.0 based ECAPA-TDNN size by approximately 76.2%, and
reduce the SSL model's inference time by 79% while presenting an EER of 0.98%.
The proposed OS-KDFT is validated across VoxCeleb1 and VoxCeleb2 datasets and
W2V2 and HuBERT SSL models. Experiments are available on our GitHub
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