23 research outputs found
A scheme for cancelling intercarrier interference using conjugate transmission in multicarrier communication systems
To mitigate intercarrier interference (ICI), a two-path algorithm is developed for multicarrier communication systems, including orthogonal frequency division multiplexing (OFDM) systems. The first path employs the regular OFDM algorithm. The second path uses the conjugate transmission of the first path. The combination of both paths forms a conjugate ICI cancellation scheme at the receiver. This conjugate cancellation (CC) scheme provides (1) a high signal to interference power ratio (SIR) in the presence of small frequency offsets (50 dB and 33 dB higher than that of the regular OFDM and linear self-cancellation algorithms [1], [2], respectively, at ΔfT = 0.1% of subcarrier frequency spacing); (2) better bit error rate (BER) performance in both additive white Gaussian noise (AWGN) and fading channels; (3) backward compatibility with the existing OFDM system; (4) no channel equalization is needed for reducing ICI, a simple low cost receiver without increasing system complexity. Although the two-path transmission reduces bandwidth efficiency, the disadvantage can be balanced by increasing signal alphabet sizes
Otocephaly
Otocephaly is a rare lethal syndrome of microstomia, aglossia, agnathia, and synotia. This male infant was born to a 19-year-old, gravida 1, para 0, woman who received routine prenatal check-up. Polyhydramnios, low-lying ears, and proboscis were noted by sonography at 29 weeks of gestation. Amniocentesis showed a normal karyotype of 46, XY. Premature rupture of membranes and preterm labor were noted at 32 weeks of gestation. A male infant was delivered preterm and died shortly after birth. The infant showed midline proboscis and absence of mandible. The simple, soft ears were extremely low-set and were near the midline of the neck. Otocephaly is regarded as the most severe form of first arch anomalies. Prenatal diagnosis should be dependent on ultrasound analysis. In the face of polyhydramnios, otocephaly is one of the possible fetal anomalies
Towards Assumption-free Bias Mitigation
Despite the impressive prediction ability, machine learning models show
discrimination towards certain demographics and suffer from unfair prediction
behaviors. To alleviate the discrimination, extensive studies focus on
eliminating the unequal distribution of sensitive attributes via multiple
approaches. However, due to privacy concerns, sensitive attributes are often
either unavailable or missing in real-world scenarios. Therefore, several
existing works alleviate the bias without sensitive attributes. Those studies
face challenges, either in inaccurate predictions of sensitive attributes or
the need to mitigate unequal distribution of manually defined non-sensitive
attributes related to bias. The latter requires strong assumptions about the
correlation between sensitive and non-sensitive attributes. As data
distribution and task goals vary, the strong assumption on non-sensitive
attributes may not be valid and require domain expertise. In this work, we
propose an assumption-free framework to detect the related attributes
automatically by modeling feature interaction for bias mitigation. The proposed
framework aims to mitigate the unfair impact of identified biased feature
interactions. Experimental results on four real-world datasets demonstrate that
our proposed framework can significantly alleviate unfair prediction behaviors
by considering biased feature interactions
Significance of Coronary Calcification for Prediction of Coronary Artery Disease and Cardiac Events Based on 64-Slice Coronary Computed Tomography Angiography
This work aims to validate the clinical significance of coronary artery calcium score (CACS) in predicting coronary artery disease(CAD) and cardiac events in 100 symptomatic patients (aged 37–87 years, mean 62.5, 81 males) that were followed up for a mean of 5 years. Our results showed that patients with CAD and cardiac events had significantly higher CACS than those without CAD and cardiac events, respectively. The corresponding data were 1450.42 ± 3471.24 versus 130 ± 188.29 (P 1000. Increased CACS (>100)was also associated with an increased frequency of multi-vessel disease. Nonetheless, 3 (20%) out of 15 patients with zero CACS had single-vessel disease. Significant correlation (P < 0.001) was observed between CACS and CAD on a vessel-based analysis for coronary arteries. It is concluded that CACS is significantly correlated with CAD and cardiac events
DiscoverPath: A Knowledge Refinement and Retrieval System for Interdisciplinarity on Biomedical Research
The exponential growth in scholarly publications necessitates advanced tools
for efficient article retrieval, especially in interdisciplinary fields where
diverse terminologies are used to describe similar research. Traditional
keyword-based search engines often fall short in assisting users who may not be
familiar with specific terminologies. To address this, we present a knowledge
graph-based paper search engine for biomedical research to enhance the user
experience in discovering relevant queries and articles. The system, dubbed
DiscoverPath, employs Named Entity Recognition (NER) and part-of-speech (POS)
tagging to extract terminologies and relationships from article abstracts to
create a KG. To reduce information overload, DiscoverPath presents users with a
focused subgraph containing the queried entity and its neighboring nodes and
incorporates a query recommendation system, enabling users to iteratively
refine their queries. The system is equipped with an accessible Graphical User
Interface that provides an intuitive visualization of the KG, query
recommendations, and detailed article information, enabling efficient article
retrieval, thus fostering interdisciplinary knowledge exploration. DiscoverPath
is open-sourced at https://github.com/ynchuang/DiscoverPath
Genome-Wide Analyses of Nkx2-1 Binding to Transcriptional Target Genes Uncover Novel Regulatory Patterns Conserved in Lung Development and Tumors
The homeodomain transcription factor Nkx2-1 is essential for normal lung development and homeostasis. In lung tumors, it is considered a lineage survival oncogene and prognostic factor depending on its expression levels. The target genes directly bound by Nkx2-1, that could be the primary effectors of its functions in the different cellular contexts where it is expressed, are mostly unknown. In embryonic day 11.5 (E11.5) mouse lung, epithelial cells expressing Nkx2-1 are predominantly expanding, and in E19.5 prenatal lungs, Nkx2-1-expressing cells are predominantly differentiating in preparation for birth. To evaluate Nkx2-1 regulated networks in these two cell contexts, we analyzed genome-wide binding of Nkx2-1 to DNA regulatory regions by chromatin immunoprecipitation followed by tiling array analysis, and intersected these data to expression data sets. We further determined expression patterns of Nkx2-1 developmental target genes in human lung tumors and correlated their expression levels to that of endogenous NKX2-1. In these studies we uncovered differential Nkx2-1 regulated networks in early and late lung development, and a direct function of Nkx2-1 in regulation of the cell cycle by controlling the expression of proliferation-related genes. New targets, validated in Nkx2-1 shRNA transduced cell lines, include E2f3, Cyclin B1, Cyclin B2, and c-Met. Expression levels of Nkx2-1 direct target genes identified in mouse development significantly correlate or anti-correlate to the levels of endogenous NKX2-1 in a dosage-dependent manner in multiple human lung tumor expression data sets, supporting alternative roles for Nkx2-1 as a transcriptional activator or repressor, and direct regulator of cell cycle progression in development and tumors
Numerosol A–D, New Cembranoid Diterpenes from the Soft Coral Sinularia numerosa
Four new cembrane-type diterpenes; numerosol A–D (1–4); along with a known steroid; gibberoketosterol (5); were isolated from the Taiwanese soft coral Sinularia numerosa. The structures of these metabolites were determined by extensive analysis of spectroscopic data. Gibberoketosterol (5) exhibited cytotoxicity against P-388 (mouse lymphocytic leukemia) cell line with an ED50 of 6.9 μM