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

Effects of a multi-herbal extract on type 2 diabetes

<p>Abstract</p> <p>Background</p> <p>An aqueous extract of multi-hypoglycemic herbs of <it>Panax ginseng </it>C.A.Meyer, <it>Pueraria lobata, Dioscorea batatas Decaisne, Rehmannia glutinosa, Amomum cadamomum Linné, Poncirus fructus </it>and <it>Evodia officinalis </it>was investigated for its anti-diabetic effects in cell and animal models.</p> <p>Methods</p> <p>Activities of PPARγ agonist, anti-inflammation, AMPK activator and anti-ER stress were measured in cell models and in <it>db/db </it>mice (a genetic animal model for type 2 diabetes).</p> <p>Results</p> <p>While the extract stimulated PPARγ-dependent luciferase activity and activated AMPK in C2C12 cells, it inhibited TNF-α-stimulated IKKβ/NFkB signaling and attenuated ER stress in HepG2 cells. The <it>db/db </it>mice treated with the extract showed reduced fasting blood glucose and HbA_1clevels, improved postprandial glucose levels, enhanced insulin sensitivity and significantly decreased plasma free fatty acid, triglyceride and total cholesterol.</p> <p>Conclusion</p> <p>The aqueous extract of these seven hypoglycemic herbs demonstrated many therapeutic effects for the treatment of type 2 diabetes in cell and animal models.</p

Anti-malarial activity of 6-(8'Z-pentadecenyl)-salicylic acid from Viola websteri in mice

<p>Abstract</p> <p>Background</p> <p>Petroleum ether extracts of <it>Viola websteri </it>Hemsl (Violaceae) were reported to have anti-plasmodial activity against <it>Plasmodium falciparum in vitro</it>, with this activity being largely attributable to 6-(8'Z-pentadecenyl)-salicylic acid (6-SA).</p> <p>Methods</p> <p>The schizontocidal activity of 6-SA on early <it>Plasmodium berghei </it>infections was evaluated in a four-day test. The possible 'repository' activity of 6-SA was assessed using the method described by Peters. The median lethal dose (LD₅₀) of 6-SA, when given intraperitoneally, was also determined using uninfected ICR mice and the method of Lorke.</p> <p>Results</p> <p>In the present study, 6-SA was found to have anti-malarial activity <it>in vivo</it>, when tested against <it>P. berghei </it>in mice. 6-SA at 5, 10 and 25 mg/kg·day exhibited a significant blood schizontocidal activity in four-day early infections, repository evaluations and established infections with a significant mean survival time comparable to that of the standard drug, chloroquine (5 mg/kg·day).</p> <p>Conclusion</p> <p>6-SA possesses a moderate anti-malarial activity that could be exploited for malaria therapy.</p

Fabrication of AlGaN/GaN Fin-Type HEMT Using a Novel T-Gate Process for Improved Radio-Frequency Performance

To increase the radio-frequency (RF) performance of AlGaN/GaN-based fin-type high electron mobility transistors (HEMTs), a novel T-gate process was developed and applied to fabricate a device with high RF performance. In a single lithography process, the applied T-gate process shows a technique for forming a T-gate using the reactivity difference of several photoresists. The fabricated device has a steep fin width (W-fin) of 130 nm, a fin height (H-fin) of 250 nm, and a gate length (L-G) of 190 nm. The device exhibits a low leakage current (I-off) of 6.6 x 10(-10) A/mm and a high I-on/I-off current ratio of 4.7 x 10(8). Moreover, the fabricated device achieved a high cut-off frequency (f(T)) of 9.7 GHz and a very high maximum oscillation frequency (f(max)) of 27.8 GHz. The f(max) value of the proposed device is 138% higher than that of GaN-based fin-type HEMTs without T-gate.1

A Novel Process for Extracting Precious Metals from Spent Mobile Phone PCBs and Automobile Catalysts

A novel process to simultaneously extract the precious metals such as gold, silver, platinum, palladium and rhodium from spent mobile phone printed circuit boards (PCBs) and honeycomb-type auto catalysts by smelting using waste-copper slag without adding any collector metals or by-products such as dross, matte and slime has been developed. In the process, waste-copper slag which is an industrial waste discharged from copper smelter is used not only as a flux for controlling slag composition, but also as a collector metal for capturing precious metals, and a plastic component contained in spent mobile phone PCBs is done as a reducing agent of iron oxides contained in the waste-copper slag. Using the developed process, up to 95% of gold, silver, platinum, palladium and rhodium contained in the raw materials were extracted in a CuFeSn alloy phase, respectively

In vitro antioxidant and anti-adipogenic effects of slendesta, standard potato extracts containing 5% protease inhibitor II

Background: The objective of the present study is to observe the anti-adipogenic effects of Slendesta (SLD), a standard potato protein extracts containing 5% potato protease inhibitor II (PI2) on the 3T3-L1 preadipocytes which are able to differentiate into mature adipocytes and accumulate lipids, as an obesity model with cytotoxicity and antioxidant effects.Materials and Methods: The cytotoxicity of SLD was observed against 3T3-L1 preadipocyte cell line by MTT assay, and also antiadipogenic effects were observed through lipid accumulation assay during 3T3-L1 differentiation as comparing with N-Acetyl-Lcysteine (NAC). In addition, antioxidant effects of SLD were detected by free radical scavenging capacity and superoxide dismutase (SOD)-like activity as comparing with ascorbic acid.Results: The SLD showed obvious cytotoxicity against 3T3-L1 pre-adipocyte cell line at higher concentrations, from 1.5 mg/ml for 72 h treatment, and the cytotoxic IC50 of SLD after 24, 48 and 72 h treatment times were detected as 10.11 ± 0.67, 5.71 ± 0.37 and 5.34 ± 0.21 mg/ml, respectively. The SLD also concentration-dependently inhibited the lipid accumulations formatted during 3T3-L1 cell differentiations. The adipogenic specific genes including PPARγ, C/EBPα, C/EBPβ and leptin were found to be reduced in SLD and NAC-treated cells compared to control cells. Furthermore, the SLD effectively showed DPPH radical scavenging activity (IC50 = 161.98 ± 64.65 μg/ml) and SOD-like effects (IC50 = 284.54 ± 54.47 μg/ml), and the cellular ROS was significantly inhibited in the SLD-treated cells compared to control cells.Conclusion: The results suggest that SLD effectively inhibit the differentiations of 3T3-L1 preadipose cell probably through antioxidant activities and direct cytotoxicity in case of higher concentration, along with satiety effects mediated by increases of circulating cholecystokinin. These findings are considered as direct evidences that SLD may serve as a predictable functional ingredient for obesity as an alternative therapy.Key words: Slendesta, potato protease inhibitor II, 3T3-L1 cell, cytotoxicity, anti-adipogenic effects, antioxidant effects

Prostate Specific Membrane Antigen mRNA in Blood as a Potential Predictor of Biochemical Recurrence after Radical Prostatectomy

We investigated whether the detection of prostate specific membrane antigen (PSMA) in blood preoperatively has predictive value for biochemical recurrence (BCR) after radical prostatectomy in patients with prostate cancer. All 134 patients scheduled to receive radical prostatectomy for prostate cancer were prospectively enrolled. The authors used nested reverse transcriptase-polymerase chain reaction (RT-PCR) assay to detect PSMA mRNA-bearing cells in peripheral blood, and analyzed the ability of PSMA mRNA positivity to predict BCR after surgery. PSMA-mRNA was detected in 24 (17.9%) patients by RT-PCR. Over a median follow-up of 20 months (range, 3 to 46 months), BCR developed in 15 patients (11.2%) and median time to BCR was 7 months (range, 3 to 25 months). Kaplan-Meier analysis revealed a significant difference between those positive or negative for PSMA in terms of recurrence-free actuarial probability (log rank P=0.0039). Multivariate analysis showed that positivity for PSMA mRNA (HR: 3.697, 95% CI 1.285-10.634, P=0.015) and a biopsy Gleason score of ≥7 (HR: 4.500, 95% CI 1.419-14.274, P=0.011) were independent preoperative predictors of BCR. The presence of PSMA mRNA in peripheral blood can be used to predict BCR after radical prostatectomy

Cause of Chest Pain in a Patient with Previous Myocardial Infarction: Look Outside the Heart for Extracardiac Mass

We report a case of thymic carcinoma that was initially detected by echocardiography in an 80-year-old male who visited the emergency room for chest pain and had a history of myocardial infarction and percutaneous coronary intervention. Transthoracic echocardiography showed a huge extracardiac mass that was located in the anterior mediastinum and was diagnosed as a thymic carcinoma by biopsy