281 research outputs found
Improving Term Frequency Normalization for Multi-topical Documents, and Application to Language Modeling Approaches
Term frequency normalization is a serious issue since lengths of documents
are various. Generally, documents become long due to two different reasons -
verbosity and multi-topicality. First, verbosity means that the same topic is
repeatedly mentioned by terms related to the topic, so that term frequency is
more increased than the well-summarized one. Second, multi-topicality indicates
that a document has a broad discussion of multi-topics, rather than single
topic. Although these document characteristics should be differently handled,
all previous methods of term frequency normalization have ignored these
differences and have used a simplified length-driven approach which decreases
the term frequency by only the length of a document, causing an unreasonable
penalization. To attack this problem, we propose a novel TF normalization
method which is a type of partially-axiomatic approach. We first formulate two
formal constraints that the retrieval model should satisfy for documents having
verbose and multi-topicality characteristic, respectively. Then, we modify
language modeling approaches to better satisfy these two constraints, and
derive novel smoothing methods. Experimental results show that the proposed
method increases significantly the precision for keyword queries, and
substantially improves MAP (Mean Average Precision) for verbose queries.Comment: 8 pages, conference paper, published in ECIR '0
Feature Structure Distillation for BERT Transferring
Knowledge distillation is an approach to transfer information on
representations from a teacher to a student by reducing their difference. A
challenge of this approach is to reduce the flexibility of the student's
representations inducing inaccurate learning of the teacher's knowledge. To
resolve it in BERT transferring, we investigate distillation of structures of
representations specified to three types: intra-feature, local inter-feature,
global inter-feature structures. To transfer them, we introduce \textit{feature
structure distillation} methods based on the Centered Kernel Alignment, which
assigns a consistent value to similar features structures and reveals more
informative relations. In particular, a memory-augmented transfer method with
clustering is implemented for the global structures. In the experiments on the
nine tasks for language understanding of the GLUE dataset, the proposed methods
effectively transfer the three types of structures and improve performance
compared to state-of-the-art distillation methods. Indeed, the code for the
methods is available in https://github.com/maroo-sky/FSDComment: This work has been submitted to the IEEE for possible publication.
Copyright may be transferred without notice, after which this version may no
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Stress-induced Cardiomyopathy during Pulmonary Resection (Takotsubo Syndrome) - A case report -
Stress-induced cardiomyopathy is caused by emotional or physical stressors and mimics acute myocardial infarction, though Stress-induced cardiomyopathy is characterized by reversible left ventricular (LV) apical ballooning in the absence of significant coronary artery disease. We describe a 51-year-old male who underwent left upper lobectomy for non-small cell lung cancer, and during which cardiogenic arrest occurred due to stress-induced cardiomyopathy, successfully managed by intra-aortic balloon pumping and extracorporeal membrane oxygenation
An Isolated True Aneurysm of the Superficial Femoral Artery in a Young Woman - A case report -
A 39-year-old woman was admitted to the hospital due to a pulsatile mass on her right inner thigh that was evident for two months. She did not exhibit any risk factors of atherosclerosis, no evidence of vasculitis, or any signs of previous trauma history. Ultrasound and computed tomography revealed an adult fist-sized aneurysm on the distal superficial femoral artery. The aneurysm was resected and peripheral circulation was restored with the interposition of a saphenous vein graft. The resected aneurysm had three layers that showed atherosclerosis on histological examination
Leadership Succession Planning: An Examination of Sole Proprietor Estate Surveying and Valuation Firms in Lagos Metropolis, Nigeria
This paper reports the results from a survey of 38 small sole- proprietor estate surveying and valuation firms in Lagos, Nigeria. A 45% questionnaire retrieval rate was achieved while CEOs/owners of estate surveying and valuation firms were interviewed. Descriptive statistics were used to analyze the respondentsā general characteristics as well as their attitude toward business succession planning. The study found that sole-proprietor firm owners desired that their firms outlive them through transferring of the firmsā businesses to their next generation. However, majority of these sole proprietorsā next generation were not keen on pursuing real estate business related courses in their undergraduate days in view of their exposure to modern technology and the influence of peers. Also, the study found that the owners of these firms have not, as a matter of policy, planned for their succession because of the cultural and attitudinal beliefs and values, which forbid thoughts about death or incapacitation about a living soul. As a result, the study indicated that only 5% of sole proprietor estate surveying and valuation firms in this category have continued to the second generation in the study area. This outcome has serious implications for small professional service businessesā economic and job creation potential for Nigeria
Orthotopic transplantation of retinoblastoma cells into vitreous cavity of zebrafish for screening of anticancer drugs
BACKGROUND: With high throughput screening, novel therapeutic agents can be efficiently identified. Unfortunately, researchers only resort to in vitro cell viability assays for screening of anticancer drugs for retinoblastoma, the most common intraocular cancer in the childhood. Current available animal models of retinoblastoma require more than 2 weeks for tumour formation and the investigation of the efficacy of therapeutic agents. In this study, we established a novel orthotopic transplantation model of retinoblastoma in zebrafish as an in vivo animal model for screening of anticancer drugs. METHODS: We injected retinoblastoma cells into the vitreous cavity of zebrafish at 48 hours after fertilization. Eyeballs of zebrafish were scanned daily under the confocal laser microscope, and the tumor population was quantitatively analyzed by measuring the mean intensity of green fluorescent protein (GFP). Transplanted retinoblastoma cells were isolated to perform further analyses including Western blotting and reverse transcriptase-polymerase chain reaction to confirm that retinoblastoma cells maintained their characteristics as tumor cells even after transplantation and further isolation. To figure out the potential of this model for screening of anticancer drugs, zebrafish were cultured in Ringerās solution containing carboplatin and melphalan after the injection of retinoblastoma cells. RESULTS: The degree of the tumor population was dependent on the number of retinoblastoma cells injected and maintained stably for at least 4 days. Transplanted retinoblastoma cells maintain their proliferative potential and characteristics as retinoblastoma cells after isolation. Interestingly, systemic application of carboplatin and melphalan demonstrated significant reduction in the tumor population, which could be quantitatively analyzed by the estimation of the mean intensity of GFP. CONCLUSIONS: This orthotopic retinoblastoma model in zebrafish is expected to be utilized for the screening of anticancer drugs for the treatment of retinoblastoma
Breast cancer cell debris diminishes therapeutic efficacy through heme oxygenase-1-mediated inactivation of M1-like tumor-associated macrophages
Chemotherapy is commonly used as a major therapeutic option for breast cancer treatment, but its efficacy is often diminished by disruption of patient's anti-tumor immunity. Chemotherapy-generated tumor cell debris could hijack accumulated tumor-associated macrophages (TAMs), provoking tumor recurrence. Therefore, reprogramming TAMs to acquire an immunocompetent phenotype is a promising strategy to potentiate therapeutic efficacy. In this study, we analyzed the proportion of immune cells in the breast cancer patients who received chemotherapy. To validate our findings in vivo, we used a syngeneic murine breast cancer (4T1) model. Chemotherapy generates an immunosuppressive tumor microenvironment in breast cancer. Here, we show that phagocytic engulfment of tumor cell debris by TAMs reduces chemotherapeutic efficacy in a 4T1 breast cancer model. Specifically, the engulfment of tumor cell debris by macrophages reduced M1-like polarization through heme oxygenase-1 (HO-1) upregulation. Conversely, genetic or pharmacologic inhibition of HO-1 in TAMs restored the M1-like polarization. Our results demonstrate that tumor cell debris-induced HO-1 expression in macrophages regulates their polarization. Inhibition of HO-1 overexpression in TAMs may provoke a robust anti-tumor immune response, thereby potentiating the efficacy of chemotherapy.
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