• Title/Summary/Keyword: P-y models

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Using High Resolution Ecological Niche Models to Assess the Conservation Status of Dipterocarpus lamellatus and Dipterocarpus ochraceus in Sabah, Malaysia

  • Maycock, Colin R.;Khoo, Eyen;Kettle, Chris J.;Pereira, Joan T.;Sugau, John B.;Nilus, Reuben;Jumian, Jeisin;Burslem, David F.R.P.
    • Journal of Forest and Environmental Science
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    • v.28 no.3
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    • pp.158-169
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    • 2012
  • Sabah has experienced a rapid decline in the extent of forest cover. The precise impact of habitat loss on the conservation status of the plants of Sabah is uncertain. In this study we use the niche modelling algorithm MAXENT to construct preliminary, revised and final ecological niche models for Dipterocarpus lamellatus and Dipterocarpus ochraceus and combined these models with data on current land-use to derive conservation assessments for each species. Preliminary models were based on herbarium data alone. Ground surveys were conducted to evaluate the performance of these preliminary models, and a revised niche model was generated from the combined herbarium and ground survey data. The final model was obtained by constraining the predictions of the revised models by filters. The range overlap between the preliminary and revised models was 0.47 for D. lamellatus and 0.39 for D. ochraceus, suggesting poor agreement between them. There was substantial variation in estimates of habitat loss for D. ochraceus, among the preliminary, revised and constrained models, and this has the potential to lead to incorrect threat assessments. From these estimates of habitat loss, the historic distribution and estimates of population size we determine that both species should be classified as Critically Endangered under IUCN Red List guidelines. Our results suggest that ground-truthing of ecological niche models is essential, especially if the models are being used for conservation decision making.

Neuroprotection by Valproic Acid in Mouse Models of Permanent and Transient Focal Cerebral Ischemia

  • Qian, Yong Ri;Lee, Mu-Jin;Hwang, Shi-Nae;Kook, Ji-Hyun;Kim, Jong-Keun;Bae, Choon-Sang
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.6
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    • pp.435-440
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    • 2010
  • Valproic acid (VPA) is a well-known anti-epileptic and mood stabilizing drug. A growing number of reports demonstrate that VPA is neuroprotective against various insults. Despite intensive efforts to develop new therapeutics for stroke over the past two decades, all treatments have thus far failed to show clinical effect because of treatment-limiting side effects of the drugs. Therefore, a safety-validated drug like VPA would be an attractive candidate if it has neuroprotective effects against ischemic insults. The present study was undertaken to examine whether pre- and post-insult treatments with VPA protect against brain infarct and neurological deficits in mouse transient (tMCAO) and permanent middle cerebral artery occlusion (pMCAO) models. In the tMCAO (2 hr MCAO and 22 hr reperfusion) model, intraperitoneal injection of VPA (300 mg/kg, Lp.) 30 min prior to MCAO significantly reduced the infarct size and the neurological deficit. VPA treatment immediately after reperfusion significantly reduced the infarct size. The administration of VPA at 4 hr after reperfusion failed to reduce the infarct size and the neurological deficit. In the pM CAO model, treatment with VPA (300 mg/kg, i.p.) 30 min prior to MCAO significantly attenuated the infarct size, but did not affect the neurological deficit. Western blot analysis of acetylated H3 and H4 protein levels in extracts from the ischemic cortical area showed that treatment with VPA increased the expression of acetylated H3 and H4 at 2 hrs after MCAO. These results demonstrated that treatment with VPA prior to ischemia attenuated ischemic brain damage in both mice tMCAO and pMCAO models and treatment with VPA immediately after reperfusion reduced the infarct area in the tMCAO model. VPA could therefore be evaluated for clinical use in stroke patients.

Association Analysis between Polymorph isms of NOTCH4 Gene and Schizophrenia in Korean Population

  • Lee, Seo-Kyong;Kang, Sung-Wook;Kim, Su-Kang;Kim, Hak-Jae;Kim, Tae;Park, Jin-Kyung;Cho, Ah-Rang;Kim, Jong-Woo;Park, Hyun-Kyung;Kim, Youn-Jung;Choe, Bong-Keun;Song, Ji-Young
    • Molecular & Cellular Toxicology
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    • v.5 no.2
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    • pp.160-164
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    • 2009
  • Notch signaling plays a crucial role in development of the nervous system. Neurodevelopmental hypothesis on etiology of schizophrenia has been implicated. The aim of this study is to determine whether single nucleotide polymorphisms (SNPs) of Notch homolog 4 (Drosophila) (NOTCH4) gene are associated with schizophrenia. This study included 283 schizophrenia patients diagnosed according to DSM-IV and 301 normal control subjects. Control subjects without history of psychiatric disorders were recruited. Four missense SNPs [rs915894 (exon 3, Lys117Gln), rs2071282 (exon 4, Pro204Leu), rs422951 (exon 6, Thr320Ala), and rs17604492 (exon 18, Gly942Arg)] of NOTCH4 gene were genotyped by the direct sequencing method. Multiple logistic regression models (codominant, dominant, and recessive models) were employed to evaluate odds ratio, 95% confidence interval, and p value. For analysis of genetic data, SNPStats, Haploview, HapAnalyzer, SNPAnalyzer, and Helixtree programs were also used. Of 4 SNPs, rs2071282 was weekly associated with schizophrenia in two alternative models (codominant model, P=0.049; dominant, P=0.041). However, these associations were not significant after Bonferroni correction. At 4 SNPs, one linkage disequilibrium (LD) block was made. This block consisted of rs915894 and rs2071282. In haplotype analysis, AC haplotype was weakly associated with schizophrenia (dominant, P=0.04). This association was disappeared after Bonferroni correction. Our result shows possibility that some SNPs of NOTCH4 gene may be weekly associated with development of schizophrenia in Korean population. However, replication result by other population will be needed.

Adsorption of methylene blue from an aqueous dyeing solution by use of santa barbara amorphous-15 nanostructure: Kinetic and isotherm studies

  • Alizadeh, Reza;Zeidi, Amir
    • Advances in environmental research
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    • v.6 no.2
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    • pp.113-125
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    • 2017
  • Santa Barbara Amorphous-15(SBA-15) nanoparticles were utilized as the inexpensive and effective adsorbents to remove methylene blue dye from the aqueous solution.SBA-15 was created by Zhao et al method. Infrared spectroscopy, X-ray diffraction and scanning electron microscopy (SEM) were used for the evaluated physical properties of SBA-15. The results of diffraction X-ray indicated that was the crystalline structure for it. Also IR spectroscopy indicated was a silica the whole structure of the groups and SEM image verify the structure of relatively identical particles size of SBA-15. Factors affecting adsorption including the amounts of adsorbent, pH and contact time were investigated by a SBA-15 nanomaterial design. The extent of dye removal enhanced with increasing initial dye concentration and pH from 4 to 10. The higher percentage adsorption were obtained under optimum conditions of variables (sorbent dose of 200 mg/liter, initial MB concentration 10 mg/liter, initial pH of 10 and temperature of $25^{\circ}C$). Maximum adsorption happened after the 2 hour and the kinetic processes of the dyes adsorption were described by applying the pseudo-first-order and the pseudo-second-order and the relatively High correlation with the kinetic Ellovich models. It was found that the pseudo-second-order models kinetic equation described the data of dye adsorption with a good correlation (R2>0.999) which indicated chemisorption mechanism. Freundlich and Langmuir adsorption models were investigated in conditions of variables (adsorbent dose 0.01 gr/liter, MB concentration 10, 20, 30 mg/liter, pH of 4, 7, 10, contact time 90 min and temperature of $27^{\circ}C$). The adsorption data were represented by Langmuir isotherm model. These values are higher than the adsorption capacities of some other adsorbents that have recently been published in the literature.

Insulin-like Growth Factor-1, IGF-binding Protein-3, C-peptide and Colorectal Cancer: a Case-control Study

  • Joshi, Pankaj;Joshi, Rakhi Kumari;Kim, Woo Jin;Lee, Sang-Ah
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3735-3740
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    • 2015
  • Context: Insulin-like growth factor peptides play important roles in regulating cell growth, cell differentiation, and apoptosis, and have been demonstrated to promote the development of colorectal cancer (CRC). Objective: To examine the association of insulin-related biomarkers including insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) and C-peptide with CRC risk and assess their relevance in predictive models. Materials and Methods: The odds ratios of colorectal cancer for serum levels of IGF-1, IGFBP-3 and C-peptide were estimated using unconditional logistic regression models in 100 colorectal cancer cases and 100 control subjects. Areas under the receiving curve (AUC) and integrated discrimination improvement (IDI) statistics were used to assess the discriminatory potential of the models. Results: Serum levels of IGF-1 and IGFBP-3 were negatively associated with colorectal cancer risk (OR=0.07, 95%CI: 0.03-0.16, P for trend <.01, OR=0.06, 95%CI: 0.03-0.15, P for trend <.01 respectively) and serum C-peptide was positively associated with risk of colorectal cancer (OR=4.38, 95%CI: 2.13-9.06, P for trend <.01). Compared to the risk model, prediction for the risk of colorectal cancer had substantially improved when all selected biomarkers IGF-1, IGFBP-3 and inverse value of C-peptide were simultaneously included inthe reference model [P for AUC improvement was 0.02 and the combined IDI reached 0.166% (95 % CI; 0.114-0.219)]. Conclusions: The results provide evidence for an association of insulin-related biomarkers with colorectal cancer risk and point to consideration as candidate predictor markers.

Analgesic Effect of DA-5018, a New Capsaicin Derivative, against Experimental Acute Pain (새로운 캅사이신 유도체 DA-5018의 급성통증 모델에서의 진통작용)

  • 손문호;배은주;김희기;신명수;김순희;김원배;양중의;박노상
    • Biomolecules & Therapeutics
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    • v.5 no.1
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    • pp.67-73
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    • 1997
  • Analgesic effect of DA-5018, a new capsaicin derivative, was evaluated in various rat models of experimentally induced acute pain. DA-5018(0.2∼10.0 mg/kg, p.o.) prevented the writhing syndromes induced by acetic acid or phenol-p-benzoquinone(PBQ). It increased the pain threshold of inflamed paw when tested by the Randall-Selitto method at the dose of 2.0∼20.0 mg/kg by oral administration. And also it showed antinociceptive activities in tail-pinch(1.0∼20.0 mg/kg, p.o.) and tail-flick test(5.0∼50.0 mg/kg, p.o.). the potency and efficacy of DA-5018 were comparable to morphine · HCI in all the models mentioned above. Acetaminophen exhibited the inhibition of acetic acid-induced writhing syndromes and also analgesic activity in Randall-Selitto test, but it showed the limited efficacy in tail-pinch and tail-flick test. These results mean that DA-5018 has a broader analgesic activity profile than acetaminophen. And we found out that the analgesic activity of DA-5018 was 100 times more potent when administered centrally than administered orally in tail-flick test. These results suggest that DA-5018 has an orally active analgesic activity, and central nervous system may be involved in the action of DA-5018.

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HYSTERETIC MODELING ON THE CONVECTIVE TRANSPORT OF ORGANIC SOLVENT IN AN UNSATURATED SOIL ZONE

  • Lee, Kun-Sang
    • Environmental Engineering Research
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    • v.11 no.5
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    • pp.241-249
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    • 2006
  • A mathematical model is described for the prediction of convective upward transport of an organic solvent driven by evaporation at the surface, which is known as the major transport mechanism in the in-situ photolysis of a soil contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD). A finite-element model was proposed to incorporate the effects of multiphase flow on the distribution of each fluid, gravity as a driving force, and the use of hysteretic models for more accurate description of k-S-p relations. Extensive numerical calculations were performed to study fluid flow through three types of soils under different water table conditions. Predictions of relative permeability-saturation-pressure (k-S-p) relations and fluids distribution for an illustrative soil indicate that hysteresis effects may be quite substantial. This result emphasizes the need to use hysteretic models in performing flow simulations including reversals of flow paths. Results of additional calculations accounting for hysteresis on the one-dimensional unsaturated soil columns show that gravity affects significantly on the flow of each fluid during gravity drainage, solvent injection, and evaporation, especially for highly permeable soils. The rate and duration of solvent injection also have a profound influence on the fluid saturation profile and the amount of evaporated solvent. Key factors influencing water drainage and solvent evaporation in soils also include hydraulic conductivity and water table configuration.

Mathematical Properties of the Formulas Evaluating Boolean Operators in Information Retrieval (정보검색에서 부울연산자를 연산하는 식의 수학적 특성)

  • 이준호;이기호;조영화
    • Journal of the Korean Society for information Management
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    • v.12 no.1
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    • pp.87-97
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    • 1995
  • Boolean retrieval systems have been most widely used in the area of information retrieval due to easy implementation and efficient retrieval. Conventional Boolean retrieval systems. however, cannot rank retrieved documents in decreasing order of query-document similarities because they cannot compute similarity coefficients between queries and documents. Extended Boolean models such as fuzzy set. Waller-Kraft, Paice, P-Norm and Infinite-One have been developed to provide the document ranking facility. In extended Boolean models, the formulas evaluating Boolean operators AND and OR are an important component to affect the quality of document ranking. In this paper we present mathematical properties of the formulas, and analyse their effect on retrieval effectiveness. Our analyses show that P-Norm is the most suitable for achieving high retrieval effectiveness.

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ITU-R Rec. P.1546-3 Propagation Prediction model Simulator using additional transmitting parameter (송신국 파라미터를 이용한 ITU-R Rec. P.1546-3 전파예측 모델 시뮬레이터 설계)

  • Lee, Kyung-Ryang;Choi, Sung-Woong;Cha, Jae-Sang;Kim, Seong-Kweon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.6 no.2
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    • pp.157-162
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    • 2011
  • International Telecommunication Union(ITU), recommended a propagation prediction models that can be applied to a various propagation environments that many services have been established in the field of broadcasting and telecommunications using ITU-R. Each propagation prediction models are revised with the complement procedures of an expected difference of channel environment and prepared for a standard of a propagation prediction. In this research, it is possible to realized a practical propagation prediction in each transmitting station for a broadcasting environments of ITU-R Rec. P.1546-3 model, so called the point-to-area, using supplementary parameters of the transmitting station specification.

A Binomial Sampling Plans for Aphis gossypii (Hemiptera: Aphididae) in Greenhouse Cultivation of Cucumbers

  • Kang, Taek Jun;Park, Jung-Joon;Cho, Kijong;Lee, Joon-Ho
    • Horticultural Science & Technology
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    • v.30 no.5
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    • pp.596-602
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    • 2012
  • Infestations of Aphis gossypii per leaf in greenhouse cultivation of cucumbers were investigated to develop binomial sampling plans. An empirical $P_T-m$ model, $ln(m)={\alpha}+{\beta}ln[-ln(1-P_T)]$, was used to evaluate relationship between the proportion of infested leaves with ${\leq}$ T aphids per leaf ($P_T$) and mean aphid density (m). Tally thresholds (T) were set to 1, 3, 5, 7, and 9 aphids per leaf to find appropriate T in greenhouse cultivation of cucumbers. Increasing sample size had little effect on the precision of the binomial sampling plan. However, the precision increased with tally threshold. The binomial model with T = 5 provided appropriate predictions of the mean densities of A. gossypii in the greenhouse cultivation of cucumbers. Using a binomial model with T = 5 (sample size = 200), a wide range of densities (1.2 - 222.8 aphids per leaf) could be estimated with precision levels of 0.346 - 0.380 for $P_T$ values between 0.15 and 0.96. Binomial models were validated at T = 5 and 7 using 12 independent data sets. Both binomial models were robust and adequately described aphid densities; most of the independent sampling data fell within 95% confidence intervals around the prediction model.