45 results on '"Duc, Hiep"'
Search Results
2. Black Carbon Emissions, Transport and Effect on Radiation Forcing Modelling during the Summer 2019–2020 Wildfires in Southeast Australia.
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Duc, Hiep Nguyen, Azzi, Merched, Zhang, Yang, Kirkwood, John, White, Stephen, Trieu, Toan, Riley, Matthew, Salter, David, Chang, Lisa Tzu-Chi, Capnerhurst, Jordan, Ho, Joseph, Gunashanhar, Gunaratnam, and Monk, Khalia
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SOOT , *CARBON-black , *CARBON emissions , *WILDFIRES , *METEOROLOGICAL research , *AIR quality , *ATMOSPHERE - Abstract
The emission of black carbon (BC) particles, which cause atmospheric warming by affecting radiation budget in the atmosphere, is the result of an incomplete combustion process of organic materials. The recent wildfire event during the summer 2019–2020 in south-eastern Australia was unprecedented in scale. The wildfires lasted for nearly 3 months over large areas of the two most populated states of New South Wales and Victoria. This study on the emission and dispersion of BC emitted from the biomass burnings of the wildfires using the Weather Research Forecast–Chemistry (WRF–Chem) model aims to determine the extent of BC spatial dispersion and ground concentration distribution and the effect of BC on air quality and radiative transfer at the top of the atmosphere, the atmosphere and on the ground. The predicted aerosol concentration and AOD are compared with the observed data using the New South Wales Department of Planning and Environment (DPE) aethalometer and air quality network and remote sensing data. The BC concentration as predicted from the WRF–Chem model, is in general, less than the observed data as measured using the aethalometer monitoring network, but the spatial pattern corresponds well, and the correlation is relatively high. The total BC emission into the atmosphere during the event and the effect on radiation budget were also estimated. This study shows that the summer 2019–2020 wildfires affect not only the air quality and health impact on the east coast of Australia but also short-term weather in the region via aerosol interactions with radiation and clouds. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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3. Schmidt's subspace theorem for non-subdegenerate families of hyperplanes.
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Pham, Duc Hiep
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DIOPHANTINE approximation - Abstract
In this paper, we establish a Schmidt's subspace theorem for non-subdegenerate families of hyperplanes. In particular, our result improves the previous result on Schmidt's subspace type theorem for the case of non-degenerate families of hyperplanes, and furthermore, also shows the sharpness of the condition of non-subdegeneracy. As a consequence, we deduce a version of Lang's conjecture on exceptional sets in the case of complements of hyperplanes. [ABSTRACT FROM AUTHOR]
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- 2022
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4. ELLIPTIC CURVES AND $\boldsymbol {p}$ -ADIC ELLIPTIC TRANSCENDENCE.
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PHAM, DUC HIEP
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ALGEBRAIC numbers , *ALGEBRAIC fields , *ELLIPTIC functions , *ALGEBRAIC curves , *ELLIPTIC curves , *P-adic analysis , *LOGARITHMS - Abstract
We prove a necessary and sufficient condition for isogenous elliptic curves based on the algebraic dependence of p-adic elliptic functions. As a consequence, we give a short proof of the p-adic analogue of Schneider's theorem on the linear independence of p-adic elliptic logarithms of algebraic points on two nonisogenous elliptic curves defined over the field of algebraic numbers. [ABSTRACT FROM AUTHOR]
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- 2022
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5. p-adic non-commutative analytic subgroup theorem.
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Pham, Duc Hiep
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P-adic analysis , *NONCOMMUTATIVE algebras - Abstract
In this paper, we formulate and prove the so-called p-adic non-commutative analytic subgroup theorem. This result is seen as the p-adic analogue of a recent theorem given by Yafaev in [11]. [ABSTRACT FROM AUTHOR]
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- 2022
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6. Evaluation of NARCLIM 1.5 regional climate model prediction of precipitation and temperature over Eastern Australia.
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Duc, Hiep Nguyen
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ATMOSPHERIC models , *PREDICTION models , *TEMPERATURE , *ATMOSPHERIC boundary layer , *METEOROLOGICAL research , *NATURAL disasters - Published
- 2021
7. Liouville-type Theorem for Fractional Kirchhoff Equations with Weights.
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Duong, Anh Tuan and Pham, Duc Hiep
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LIOUVILLE'S theorem , *EQUATIONS - Abstract
In this paper, we prove a Liouville type theorem for stable solutions to fractional Kirchhoff equations with polynomial nonlinearities and weights. [ABSTRACT FROM AUTHOR]
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- 2021
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8. A validated emission inventory for NSW.
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Trieu, Toan, Duc, Hiep, Fuchs, David, Lisa Tzu-Chi Chang, Azzi, Merched, and Kellaghan, Ronan
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EMISSION inventories , *AUTOMOBILE emissions , *AIR pollutants , *PROCESS control systems - Published
- 2021
9. A NEW SPECIES OF THE GENUS Trigonura Sichel, 1865 (Hymenoptera: Chalcididae) FROM VIETNAM.
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Khuat Dang Long, Nguyen Duc Hiep, Dang Thi Hoa, and Tran Thi Ngat
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HYMENOPTERA , *CHALCIDIDAE , *NATURAL resources , *ORCHARDS - Abstract
Based on the specimens of chalcid parasitoid wasps collected by malaise traps set in fruit orchards in the adjacent area of Ha Noi city from 2018-2019, one new species of the genus Trigonura, T. vietnamica Long, sp. n., was described and illustrated. Two species of this genus from Vietnam are keyed, the comparative characters of the new species were also given to compare with two similar species from the Oriental Region, T. indica Narendran and T. luzonensis Narendran. [ABSTRACT FROM AUTHOR]
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- 2019
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10. Influence of the Pacific and Indian Ocean climate drivers on the rainfall in Vietnam.
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Duc, Hiep N., Bang, Ho Q., and Quang, Ngo X.
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RAINFALL anomalies , *ATMOSPHERIC circulation , *ATMOSPHERIC models , *MONSOONS , *BAYESIAN analysis - Abstract
Rainfall in Vietnam is strongly influenced by climate drivers which are caused by anomalies in sea surface temperature (SST), sea level pressure (SLP) or geopotential height in the Pacific and the Indian Ocean. This paper analyses the rainfall records at different sites in various regions of Vietnam to determine the influence of the three major climate drivers, the ENSO (El Niño–Southern Oscillation), IPO (Interdecadal Pacific Oscillation) and IOD (Indian Ocean Dipole) and their interaction on the rainfall at each of these sites. A statistical technique called Bayesian model averaging (BMA) is used to discuss and address the uncertainties problem in model and variable selection when fitting observed rainfall data with climate drivers' indices. The results show that the ENSO, IPO and IOD and their interaction overall have very minor roles in influencing the rainfall in Northern Vietnam but they have some influences on the rainfall in the central and southern parts of Vietnam. Furthermore, seasonality analysis shows the spring rainfall in Vietnam is strongly influenced by the ENSO, IOD and ENSO*IOD interaction, with ENSO*IOD interaction strongest in the north. The situation in summer is similar but the IOD is most dominant compared to the ENSO and ENSO*IOD interaction. In autumn, the IOD and ENSO influences on rainfall are weaker while the IPO has strong influence in the Central and Southern Vietnam and no climate driver has any influence in the north. And during winter, the IPO, ENSO and IPO*ENSO interaction are associated with rainfall variability across Vietnam while the IOD influence is insignificant. The results also confirm the previous studies on the teleconnection roles of SST in the Pacific and Indian Oceans on rainfall variability in Vietnam. Influence scale of climate drivers on spring rainfall at various sites in Vietnam. [ABSTRACT FROM AUTHOR]
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- 2018
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11. FIRST REPORT OF TWO GENERA Angustibracon Quicke AND Pseudospinaria Enderlein (Hymenoptera: Braconidae) FROM VIETNAM, WITH REDESCRIPTIONS OF SPECIES.
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Khuat Dang Long, Nguyen Van Dzuong, and Nguyen Duc Hiep
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SPECIES distribution , *SPECIES , *BRACONIDAE - Abstract
Two small genera of the subfamily Braconinae, Angustibracon Quicke, 1987 and Pseudospinaria Enderlein, 1905, are reported for the first time from Vietnam. Two Angustibracon species, Angustibracon leptogaster Cameron and Angustibracon maculiabdominis Zhou & You and one Pseudospinaria species, Pseudospinaria attenuata (Westwood) are newly recorded for Vietnam's braconid fauna. Additionally, the species are redescribed and illustrated. An illustrated key to the two known Augustibracon species and a mapped distribution of species in Vietnam are also given. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Long noncoding RNAs in cancer cells.
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Bach, Duc-Hiep and Lee, Sang Kook
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NON-coding RNA , *CANCER , *MACROMOLECULES , *TUMOR suppressor genes , *CANCER invasiveness , *CANCER diagnosis , *CANCER treatment , *TUMOR treatment , *BIOLOGICAL models , *COMPARATIVE studies , *DISEASE susceptibility , *GENES , *RESEARCH methodology , *MEDICAL cooperation , *GENETIC mutation , *RESEARCH , *RNA , *TUMORS , *EVALUATION research , *DISEASE progression - Abstract
Long noncoding RNA (lncRNA) has recently been investigated as key modulators that regulate many biological processes in human cancers via diverse mechanisms. LncRNAs can interact with macromolecules such as DNA, RNA, or protein to exert cellular effects and to act as either tumor promoters or tumor suppressors in various malignancies. Moreover, the aberrant expression of lncRNAs may be detected in multiple cancer phenotypes by employing the rapidly developing modern gene chip technology and bioinformatics analysis. Herein, we highlight the mechanisms of action of lncRNAs, their functional cellular roles and their involvement in cancer progression. Finally, we provide an overview of recent progress in the lncRNA field and future potential for lncRNAs as cancer diagnostic markers and therapeutics. [ABSTRACT FROM AUTHOR]
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- 2018
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13. The effect of lockdown period during COVID-19 pandemic on air quality in Sydney region.
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Duc, Hiep, Salter, David, Azzi, Merched, Jiang, Ningbo, Warren, Loredana, Riley, Matthew, White, Stephen, Trieu, Toan, Lisa Chang, and Barthelemy, Xavier
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COVID-19 pandemic , *STAY-at-home orders , *AIR quality monitoring stations - Published
- 2022
14. Synthesis and biological activity of new phthalimides as potential anti-inflammatory agents.
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Bach, Duc-Hiep, Liu, Jian-Yu, Kim, Won Kyung, Hong, Ji-Young, Park, So Hyun, Kim, Donghwa, Qin, Si-Ning, Luu, Thi-Thu-Trang, Park, Hyen Joo, Xu, Yong-Nan, and Lee, Sang Kook
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DRUG synthesis , *PHTHALIMIDES , *ANTI-inflammatory agents , *PATHOLOGICAL physiology , *PHYSIOLOGICAL effects of nitric oxide , *LIPOPOLYSACCHARIDES - Abstract
The overproduction of nitric oxide (NO) plays an important role in a variety of pathophysiological processes, including inflammation. Therefore, the suppression of NO production is a promising target in the design of anti-inflammatory agents. In the present study, a series of phthalimide analogs was synthesized, and their anti-inflammatory activities were evaluated using lipopolysaccharide (LPS)-stimulated NO production in cultured murine macrophage RAW264.7 cells. A structure-activity relationship study showed that the free hydroxyl group at C-4 and C-6 and the bulkiness of the N -substituted alkyl chain are associated with biological activity. Among the series of phthalimide derivatives, compound IIh exhibited potent inhibitory activity, with an IC 50 value of 8.7 µg/mL. Further study revealed that the inhibitory activity of compound IIh was correlated with the down-regulation of the mRNA and protein expression of LPS-stimulated inducible nitric oxide synthase (iNOS). Compound IIh also suppressed the induction of the pro-inflammatory cytokines tumor necrosis factor-α and interleukin-1β in LPS-stimulated RAW 264.7 cells. The anti-inflammatory activity of compound IIh was also found to be associated with the suppression of the Toll-like receptor (TLR)4 signaling pathway by down-regulating the activation of interferon regulatory factor 3 (IRF-3) and interferon-β and signal transducer expression. These findings demonstrate that novel phthalimides might be potential candidates for the development of anti-inflammatory agents. [ABSTRACT FROM AUTHOR]
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- 2017
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15. An improvement on the number of simplices in [formula omitted].
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Pham, Duc Hiep, Pham, Thang, and Vinh, Le Anh
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FINITE fields , *NUMBER theory , *SET theory , *GEOMETRIC congruences , *MATHEMATICAL analysis - Abstract
Let E be a set of points in F q d . Bennett et al. (2016) proved that if | E | ≫ q d − d − 1 k + 1 then E determines a positive proportion of all k -simplices. In this paper, we give an improvement of this result in the case when E is the Cartesian product of sets. Namely, we show that if E is the Cartesian product of sets and q k d k + 1 − 1 ∕ d = o ( | E | ) , the number of congruence classes of k -simplices determined by E is at least ( 1 − o ( 1 ) ) q k + 1 2 , and in some cases our result is sharp. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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16. Association of climate drivers with rainfall in New South Wales, Australia, using Bayesian Model Averaging.
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Duc, Hiep, Rivett, Kelly, MacSween, Katrina, and Le-Anh, Linh
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RAINFALL frequencies , *BAYESIAN analysis , *CLIMATOLOGY , *ECOLOGY ,EL Nino - Abstract
Rainfall in New South Wales (NSW), located in the southeast of the Australian continent, is known to be influenced by four major climate drivers: the El Niño/Southern Oscillation (ENSO), the Interdecadal Pacific Oscillation (IPO), the Southern Annular Mode (SAM) and the Indian Ocean Dipole (IOD). Many studies have shown the influences of ENSO, IPO modulation, SAM and IOD on rainfall in Australia and on southeast Australia in particular. However, only limited work has been undertaken using a multiple regression framework to examine the extent of the combined effect of these climate drivers on rainfall. This paper analysed the role of these combined climate drivers and their interaction on the rainfall in NSW using Bayesian Model Averaging (BMA) to account for model uncertainty by considering each of the linear models across the whole model space which is equal to the set of all possible combinations of predictors to find the model posterior probabilities and their expected predictor coefficients. Using BMA for linear regression models, we are able to corroborate and confirm the results from many previous studies. In addition, the method gives the ranking order of importance and the probability of the association of each of the climate drivers and their interaction on the rainfall at a site. The ability to quantify the relative contribution of the climate drivers offers the key to understand the complex interaction of drivers on rainfall, or lack of rainfall in a region, such as the three big droughts in southeastern Australia which have been the subject of discussion and debate recently on their causes. [ABSTRACT FROM AUTHOR]
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- 2017
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17. Naphthoquinone-Oxindole Alkaloids, Coprisidins A and B, from a Gut-Associated Bacterium in the Dung Beetle, Copris tripartitus.
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Soohyun Um, Duc-Hiep Bach, Bora Shin, Chan-Hong Ahn, Seong-Hwan Kim, Hea-Son Bang, Ki-Bong Oh, Sang Kook Lee, Jongheon Shin, and Dong-Chan Oh
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NAPHTHOQUINONE , *OXINDOLE alkaloids , *DUNG beetles , *STREPTOMYCES , *SODIUM/POTASSIUM ATPase , *OXIDOREDUCTASES - Abstract
Coprisidins A and B (1 and 2) were isolated from a gut-associated Streptomyces sp. in the dung beetle Copris tripartitus. Using a combination of spectroscopic techniques, the structures of the compounds were determined to be the first examples of natural naphthoquinone-oxindole alkaloids. Coprisidin A was found to inhibit the action of Na+/K+-ATPase, and coprisidin B showed activity for the induction of NAD(P)H:quinone oxidoreductase 1. [ABSTRACT FROM AUTHOR]
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- 2016
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18. Toward sustainable energy usage in the power generation and construction sectors—a case study of Australia.
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Azzi, Merched, Duc, Hiep, and Ha, Q.P.
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RENEWABLE energy sources , *POWER resources , *ELECTRIC power production , *CONSTRUCTION industry , *GREENHOUSE gas mitigation - Abstract
To be sustainable in energy usage in the future, there are two aspects that need to be considered: the energy supply or generation and the consumption side, including the closely linked construction and building industries which consume a large amount of energy. Essential requirements for energy efficiency are to produce less greenhouse gas emissions and to rely more on renewable energy sources for future sustainability. Policies for mitigation of the environment impact are having effects on both the supply and demand. While the former requires more alternate sources in smart grids and improved technologies for carbon capture and storage, the latter involves the reduction of energy wastes and greenhouse gas (GHG) emissions as prerequisites to green certification within the construction and building sector. Thus, access to sustainable, affordable, and secure energy is one of the major global strategic priorities to maintain and improve public health, sustain economic growth, and mitigate the effects of climate change. Toward this goal, many countries, including Australia, are investing in clean, efficient, reliable energy systems for a prosperous and environmentally sustainable future. Hence, exploring various options to ensure energy security by diversification of energy sources is an important step in meeting the future requirements and delivering clean energy to different industry sectors. This paper discusses options to manage the use of energy sources in the power generation and construction industries. Options for mitigation of environmental impact and for achievement of sustainable energy usage, such as building design with BIM, are discussed. [ABSTRACT FROM AUTHOR]
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- 2015
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19. Long-Term Trends in Inferred Continental Background Ozone in Eastern Australia.
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Riley, Matthew L., Jiang, Ningbo, Duc, Hiep Nguyen, and Azzi, Merched
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TROPOSPHERIC ozone , *AIR quality monitoring stations , *OZONE , *AIR masses , *K-means clustering , *ATMOSPHERIC composition - Abstract
A better understanding of background tropospheric ozone delivers multiple benefits. Robust estimates of regional background ozone are required to understand the limits of anthropogenic emissions controlling ozone reduction. Long-term estimates of background ozone assist in characterising changes in atmospheric composition and can help quantify the influence of human activity on the atmosphere. Background tropospheric ozone measurements representative of continental air masses are scarce in Australia. Here, we use k-means clustering to identify a cluster of measurements from the long-term air quality monitoring station at Oakdale, NSW, which are likely to be representative of background air. The cluster is associated with NOx-limited air masses of continental origin. From this analysis, we estimate background ozone representative of Eastern Australia. We find recent (2017–2022) mean ozone mixing ratios of 28.5 ppb and identify a statistically significant (α = 0.05) trend in the mean of +1.8 (1.0–2.8) ppb/decade. Our methods demonstrate that some long-term monitoring stations within or near urban areas can provide suitable conditions and datasets for regional Global Atmosphere Watch monitoring. [ABSTRACT FROM AUTHOR]
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- 2023
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20. ON THE TWO-PARAMETER ERDŐS–FALCONER DISTANCE PROBLEM IN FINITE FIELDS.
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CLÉMENT, FRANCOIS, MOJARRAD, HOSSEIN NASSAJIAN, PHAM, DUC HIEP, and SHEN, CHUN-YEN
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FINITE fields , *EUCLIDEAN distance , *POLYNOMIALS - Abstract
Given $E \subseteq \mathbb {F}_q^d \times \mathbb {F}_q^d$ , with the finite field $\mathbb {F}_q$ of order q and the integer $d\,\ge \, 2$ , we define the two-parameter distance set $\Delta _{d, d}(E)=\{(\|x-y\|, \|z-t\|) : (x, z), (y, t) \in E \}$. Birklbauer and Iosevich ['A two-parameter finite field Erdős–Falconer distance problem', Bull. Hellenic Math. Soc. 61 (2017), 21–30] proved that if $|E| \gg q^{{(3d+1)}/{2}}$ , then $ |\Delta _{d, d}(E)| = q^2$. For $d=2$ , they showed that if $|E| \gg q^{{10}/{3}}$ , then $ |\Delta _{2, 2}(E)| \gg q^2$. In this paper, we give extensions and improvements of these results. Given the diagonal polynomial $P(x)=\sum _{i=1}^da_ix_i^s\in \mathbb F_q[x_1,\ldots , x_d]$ , the distance induced by P over $\mathbb {F}_q^d$ is $\|x-y\|_s:=P(x-y)$ , with the corresponding distance set $\Delta ^s_{d, d}(E)=\{(\|x-y\|_s, \|z-t\|_s) : (x, z), (y, t) \in E \}$. We show that if $|E| \gg q^{{(3d+1)}/{2}}$ , then $ |\Delta _{d, d}^s(E)| \gg q^2$. For $d=2$ and the Euclidean distance, we improve the former result over prime fields by showing that $ |\Delta _{2,2}(E)| \gg p^2$ for $|E| \gg p^{{13}/{4}}$. [ABSTRACT FROM AUTHOR]
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- 2023
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21. Study of Planetary Boundary Layer, Air Pollution, Air Quality Models and Aerosol Transport Using Ceilometers in New South Wales (NSW), Australia.
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Duc, Hiep Nguyen, Rahman, Md Mahmudur, Trieu, Toan, Azzi, Merched, Riley, Matthew, Koh, Thomas, Liu, Shaohua, Bandara, Kasun, Krishnan, Vishall, Yang, Yujing, Silver, Jeremy, Kirley, Michael, White, Stephen, Capnerhurst, Jordan, and Kirkwood, John
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ATMOSPHERIC boundary layer , *AIR quality , *AIR pollution , *AIR pollution control , *AEROSOLS , *AIR pollutants , *RURAL health - Abstract
The planetary boundary layer height (PBLH) is one of the key factors in influencing the dispersion of the air pollutants in the troposphere and, hence, the air pollutant concentration on ground level. For this reason, accurate air pollutant concentration depends on the performance of PBLH prediction. Recently, ceilometers, a lidar instrument to measure cloud base height, have been used by atmospheric scientists and air pollution control authorities to determine the mixing level height (MLH) in improving forecasting and understanding the evolution of aerosol layers above ground at a site. In this study, ceilometer data at an urban (Lidcombe) and a rural (Merriwa) location in New South Wales, Australia, were used to investigate the relationship of air pollutant surface concentrations and surface meteorological variables with MLH, to validate the PBLH prediction from two air quality models (CCAM-CTM and WRF-CMAQ), as well as to understand the aerosol transport from sources to the receptor point at Merriwa for the three case studies where high PM10 concentration was detected in each of the three days. The results showed that surface ozone and temperature had a positive correlation with MLH, while relative humidity had negative correlation. For other pollutants (PM10, PM2.5, NO2), no clear results were obtained, and the correlation depended on the site and regional emission characteristics. The results also showed that the PBLH prediction by the two air quality models corresponded reasonably well with the observed ceilometer data and the cause and source of high PM10 concentration at Merriwa can be found by using ceilometer MLH data to corroborate back trajectory analysis of the transport of aerosols to the receptor point at Merriwa. Of the three case studies, one had aerosol sources from the north and north west of Merriwa in remote NSW, where windblown dust is the main source, and the other two had sources from the south and south east of Merriwa, where anthropogenic sources dominate. [ABSTRACT FROM AUTHOR]
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- 2022
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22. Background ozone level in the Sydney basin: assessment and trend analysis.
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Duc, Hiep, Azzi, Merched, Wahid, Herman, and Ha, Q. P.
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OZONE , *GEOLOGICAL basins , *AIR quality , *METROPOLITAN areas , *OXIDIZING agents , *NITROGEN oxides - Abstract
It has been recognized that the background ozone concentration in urban areas is changing over the years. This article aims to determine the background ozone level (BOL) using ambient air quality data measurements collected at some monitoring stations in the Sydney basin, Australia. A definition of background ozone in the context of the Sydney region is proposed. With this definition, it is possible to estimate the background ozone using ambient measurements of ozone and its precursors. The trend of the BOL is also estimated from the temporal ambient monitoring records as of early 1998-2005. These ozone level changes at different monitoring stations are assessed using the linear regression method. The results are shown to vary between different monitoring sites. This demonstrates that the local conditions at each site are important in determining as to whether an air quality management plan for reducing the ozone level to below the exceedance level is effective and achievable or not. Furthermore, the results obtained are compared with those obtained by the Clapp-Jenkin method, which is based on the relationship between oxidant and nitrogen oxides, assuming a stationary state of photochemical smog function. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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23. ASSOCIATIONS BETWEEN AIR POLLUTION AND HOSPITAL VISITS FOR CARDIOVASCULAR DISEASES IN THE ELDERLY IN SYDNEY USING BAYESIAN STATISTICAL METHODS.
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DUC, HIEP, JALALUDIN, BIN, and MORGAN, GEOFF
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AIR pollution , *VISITATION in hospitals , *CARDIOVASCULAR diseases , *DISEASES in older people , *BAYESIAN analysis - Abstract
Using generalized linear models (GLMs), Jalaludin et al. (2006; J. Exposure Analysis and Epidemiology 16, 225–237) studied the association between the daily number of visits to emergency departments for cardiovascular disease by the elderly (65+) and five measures of ambient air pollution. Bayesian methods provide an alternative approach to classical time series modelling and are starting to be more widely used. This paper considers Bayesian methods using the dataset used by Jalaludin et al. (2006) , and compares the results from Bayesian methods with those obtained by Jalaludin et al. (2006) using GLM methods. [ABSTRACT FROM AUTHOR]
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- 2009
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24. Visualising Daily PM10 Pollution in an Open-Cut Mining Valley of New South Wales, Australia—Part I: Identification of Spatial and Temporal Variation Patterns.
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Jiang, Ningbo, Riley, Matthew L., Azzi, Merched, Puppala, Praveen, Duc, Hiep Nguyen, and Di Virgilio, Giovanni
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SPATIAL variation , *COAL reserves , *POLLUTION , *PRINCIPAL components analysis , *WAVELETS (Mathematics) , *STRIP mining - Abstract
The Upper Hunter Valley is a major coal mining area containing approximately 40% of the currently identified total coal reserves in New South Wales (NSW), Australia. Due to the ongoing increase in mining activities, PM10 (airborne particles with an aerodynamic diameter of less than 10 micrometres) pollution has become a major air quality concern in local communities. This paper summarises the spatial and temporal variability modes of PM10 pollution in the region, based on long-term multi-site monitoring data and the application of the rotated principal component analysis (RPCA) and wavelet analysis techniques. RPCA identified two distinct air quality clusters/subregions in the valley: one in the west/northwest and the other in the southeast. Wavelet analysis revealed the annual cycle to be the most persistent temporal mode of PM10 variability in both subregions, with intermittent signals also observed at time scales of around 120, 30~90, and under 30 days. How these variation modes are related to the effects of local PM10 emissions and the influence of meteorology at different time scales deserves further attention in future work. The findings will be used in air quality reporting and forecasting in NSW. The methodology and results can also be useful for air quality research in similar regions elsewhere. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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25. Modeling anthropogenic trends in air quality data.
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Anh, Vo and Duc, Hiep
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AIR quality management , *MATHEMATICAL models - Abstract
Suggests that the long-range dependence (LRD) extraction method can be used to model the anthropogenic changes in air quality data. Assessment of air quality management practices on the basis of trends in air pollution monitoring data; Detecting of changes in air quality due to changes in emissions in the presence of meteorological fluctuations.
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- 1997
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26. Reply to comment on 'Associations between air pollution and hospital visits for cardiovascular diseases in the elderly in Sydney using Bayesian statistical methods'.
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Duc, Hiep, Jalaludin, Bin, and Morgan, Geoff
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LETTERS to the editor , *AIR pollution , *HEALTH , *CARDIOVASCULAR diseases - Abstract
A response by Geoff Morgan and colleagues to a letter to the editor about their paper "Associations Between Air Pollution and Hospital Visits for Cardiovascular Diseases in the Elderly in Sydney Using Bayesian Statistical Methods," published in a previous issue of "Australian & New Zealand Journal of Statistics," is presented.
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- 2011
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27. Spatial-Temporal Pattern of Black Carbon (BC) Emission from Biomass Burning and Anthropogenic Sources in New South Wales and the Greater Metropolitan Region of Sydney, Australia.
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Duc, Hiep Nguyen, Shingles, Kristina, White, Stephen, Salter, David, Chang, Lisa Tzu-Chi, Gunashanhar, Gunaratnam, Riley, Matthew, Trieu, Toan, Dutt, Upma, Azzi, Merched, Beyer, Kathleen, Hynes, Robert, and Kirkwood, John
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BIOMASS burning , *CARBON-black , *SOOT , *CARBONACEOUS aerosols , *PARTICULATE matter , *METEOROLOGY , *RADIATIVE forcing , *GLOBAL warming - Abstract
Biomass burnings either due to Hazards Reduction Burnings (HRBs) in late autumn and early winter or bushfires during summer periods in various part of the world (e.g., CA, USA or New South Wales, Australia) emit large amount of gaseous pollutants and aerosols. The emissions, under favourable meteorological conditions, can cause elevated atmospheric particulate concentrations in metropolitan areas and beyond. One of the pollutants of concern is black carbon (BC), which is a component of aerosol particles. BC is harmful to health and acts as a radiative forcing agent in increasing the global warming due to its light absorption properties. Remote sensing data from satellites have becoming increasingly available for research, and these provide rich datasets available on global and local scale as well as in situ aethalometer measurements allow researchers to study the emission and dispersion pattern of BC from anthropogenic and natural sources. The Department of Planning, Industry and Environment (DPIE) in New South Wales (NSW) has installed recently from 2014 to 2019 a total of nine aethalometers to measure BC in its state-wide air quality network to determine the source contribution of BC and PM2.5 (particulate Matter less than 2.5 μm in diameter) in ambient air from biomass burning and anthropogenic combustion sources. This study analysed the characteristics of spatial and temporal patterns of black carbon (BC) in New South Wales and in the Greater Metropolitan Region (GMR) of Sydney, Australia, by using these data sources as well as the trajectory HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) modelling tool to determine the source of high BC concentration detected at these sites. The emission characteristics of BC in relation to PM2.5 is dependent on the emission source and is analysed using regression analysis of BC with PM2.5 time series at the receptor site for winter and summer periods. The results show that, during the winter, correlation between BC and PM2.5 is found at nearly all sites while little or no correlation is detected during the summer period. Traffic vehicle emission is the main BC emission source identified in the urban areas but was less so in the regional sites where biomass burnings/wood heating is the dominant source in winter. The BC diurnal patterns at all sites were strongly influenced by meteorology. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
28. Induction of m6A methylation in adipocyte exosomal LncRNAs mediates myeloma drug resistance.
- Author
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Wang, Zhiming, He, Jin, Bach, Duc-hiep, Huang, Yung-hsing, Li, Zongwei, Liu, Huan, Lin, Pei, and Yang, Jing
- Subjects
- *
RNA-binding proteins , *DRUG resistance , *FAT cells , *LINCRNA , *BORTEZOMIB , *EXOSOMES - Abstract
Background: Therapeutic resistance occurs in most patients with multiple myeloma (MM). One of the key mechanisms for MM drug resistance comes from the interaction between MM cells and adipocytes that inhibits drug-induced apoptosis in MM cells; MM cells reprogram adipocytes to morph into different characterizations, including exosomes, which are important for tumor-stroma cellular communication. However, the mechanism by which exosomes mediate the cellular machinery of the vicious cycle between MM cells and adipocytes remains unclear. Methods: Adipocytes were either isolated from bone marrow aspirates of healthy donors or MM patients or derived from mesenchymal stem cells. Co-culturing normal adipocytes with MM cells was used to generate MM-associated adipocytes. Exosomes were collected from the culture medium of adipocytes. Annexin V-binding and TUNEL assays were performed to assess MM cell apoptosis. Methyltransferase activity assay and dot blotting were used to access the m6A methylation activity of methyltransferase like 7A (METTL7A). RIP, MeRIP-seq, and RNA–protein pull down for assessing the interaction between long non-cording RNAs (LncRNAs) and RNA binding proteins were performed. Adipocyte-specific enhancer of zeste homolog 2 (EZH2) knockout mice and MM-xenografted mice were used for evaluating MM therapeutic response in vivo. Results: Exosomes collected from MM patient adipocytes protect MM cells from chemotherapy-induced apoptosis. Two LncRNAs in particular, LOC606724 and SNHG1, are significantly upregulated in MM cells after exposure to adipocyte exosomes. The raised LncRNA levels in MM cells are positively correlated to worse outcomes in patients, indicating their clinical relevancy in MM. The functional roles of adipocyte exosomal LOC606724 or SNHG1 in inhibition of MM cell apoptosis are determined by knockdown in adipocytes or overexpression in MM cells. We discovered the interactions between LncRNAs and RNA binding proteins and identified methyltransferase like 7A (METTL7A) as an RNA methyltransferase. MM cells promote LncRNA package into adipocyte exosomes through METTL7A-mediated LncRNA m6A methylation. Exposure of adipocytes to MM cells enhances METTL7A activity in m6A methylation through EZH2-mediated protein methylation. Conclusion: This study elucidates an unexplored mechanism of how adipocyte-rich microenvironment exacerbates MM therapeutic resistance and indicates a potential strategy to improve therapeutic efficacy by blocking this vicious exosome-mediated cycle. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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29. Performance Evaluation of CCAM-CTM Regional Airshed Modelling for the New South Wales Greater Metropolitan Region.
- Author
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Chang, Lisa T.-C., Duc, Hiep Nguyen, Scorgie, Yvonne, Trieu, Toan, Monk, Khalia, and Jiang, Ningbo
- Subjects
- *
AIRSHEDS , *ATMOSPHERIC models , *PARTICULATE matter , *AIR quality monitoring , *DIURNAL variations in meteorology , *AIR quality - Abstract
A comprehensive evaluation of the performance of the coupled Conformal Cubic Atmospheric Model (CCAM) and Chemical Transport Model (CTM) (CCAM-CTM) for the New South Wales Greater Metropolitan Region (NSW GMR) was conducted based on modelling results for two periods coinciding with measurement campaigns undertaken during the Sydney Particle Study (SPS), namely the summer in 2011 (SPS1) and the autumn in 2012 (SPS2). The model performance was evaluated for fine particulate matter (PM2.5), ozone (O3) and nitrogen dioxide (NO2) against air quality data from the NSW Government's air quality monitoring network, and PM2.5 components were compared with speciated PM measurements from the Sydney Particle Study's Westmead sampling site. The model tends to overpredict PM2.5 with normalised mean bias (NMB) less than 20%, however, moderate underpredictions of the daily peak are found on high PM2.5 days. The PM2.5 predictions at all sites comply with performance criteria for mean fractional bias (MFB) of ±60%, but only PM2.5 predictions at Earlwood further comply with the performance goal for MFB of ±30% during both periods. The model generally captures the diurnal variations in ozone with a slight underestimation. The model also tends to underpredict daily maximum hourly ozone. Ozone predictions across regions in SPS1, as well as in Sydney East, Sydney Northwest and Illawarra regions in SPS2 comply with the benchmark of MFB of ±15%, however, none of the regions comply with the benchmark for mean fractional error (MFE) of 35%. The model reproduces the diurnal variations and magnitudes of NO2 well, with a slightly underestimating tendency across the regions. The MFE and normalised mean error (NME) for NO2 predictions fall well within the ranges inferred from other studies. Model results are within a factor of two of measured averages for sulphate, nitrate, sodium and organic matter, with elemental carbon, chloride, magnesium and ammonium being underpredicted. The overall performance of CCAM-CTM modelling system for the NSW GMR is comparable to similar model predictions by other regional airshed models documented in the literature. The performance of the modelling system is found to be variable according to benchmark criteria and depend on the location of the sites, as well as the time of the year. The benchmarking of CCAM-CTM modelling system supports the application of this model for air quality impact assessment and policy scenario modelling to inform air quality management in NSW. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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30. Source Contributions to Ozone Formation in the New South Wales Greater Metropolitan Region, Australia.
- Author
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Nguyen Duc, Hiep, Chang, Lisa T.-C., Trieu, Toan, Salter, David, and Scorgie, Yvonne
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- *
OZONE , *AIR pollutants , *AIR quality , *ATMOSPHERIC models - Abstract
Ozone and fine particles (PM2.5) are the two main air pollutants of concern in the New South Wales Greater Metropolitan Region (NSW GMR) due to their contribution to poor air quality days in the region. This paper focuses on source contributions to ambient ozone concentrations for different parts of the NSW GMR, based on source emissions across the greater Sydney region. The observation-based Integrated Empirical Rate model (IER) was applied to delineate the different regions within the GMR based on the photochemical smog profile of each region. Ozone source contribution was then modelled using the CCAM-CTM (Cubic Conformal Atmospheric model-Chemical Transport model) modelling system and the latest air emission inventory for the greater Sydney region. Source contributions to ozone varied between regions, and also varied depending on the air quality metric applied (e.g., average or maximum ozone). Biogenic volatile organic compound (VOC) emissions were found to contribute significantly to median and maximum ozone concentration in North West Sydney during summer. After commercial and domestic sources, power generation was found to be the next largest anthropogenic source of maximum ozone concentrations in North West Sydney. However, in South West Sydney, beside commercial and domestic sources, on-road vehicles were predicted to be the most significant contributor to maximum ozone levels, followed by biogenic sources and power stations. The results provide information that policy makers can use to devise various options to control ozone levels in different parts of the NSW Greater Metropolitan Region. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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- View/download PDF
31. The Dominant Role of Forkhead Box Proteins in Cancer.
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Bach, Duc-Hiep, Long, Nguyen Phuoc, Luu, Thi-Thu-Trang, Anh, Nguyen Hoang, Kwon, Sung Won, and Lee, Sang Kook
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- *
CANCER research , *FORKHEAD transcription factors , *DNA-binding proteins , *GENE expression , *PATHOLOGICAL physiology - Abstract
Forkhead box (FOX) proteins are multifaceted transcription factors that are significantly implicated in cancer, with various critical roles in biological processes. Herein, we provide an overview of several key members of the FOXA, FOXC, FOXM1, FOXO and FOXP subfamilies. Important pathophysiological processes of FOX transcription factors at multiple levels in a context-dependent manner are discussed. We also specifically summarize some major aspects of FOX transcription factors in association with cancer research such as drug resistance, tumor growth, genomic alterations or drivers of initiation. Finally, we suggest that targeting FOX proteins may be a potential therapeutic strategy to combat cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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32. AN UPDATED CHECKLIST OF Aleiodes AND Heterogamus SPECIES (Hymenoptera, Braconidae, Rogadinae) IN VIETNAM, WITH NEW RECORDS.
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Khuat Dang Long, Pham Quynh Mai, Pham Thi Nhi, Nguyen Duc Hiep, Tran Dinh Duong, and Dang Thi Hoa
- Subjects
- *
SPECIES distribution , *AGRICULTURAL pests , *PEST control , *SPECIES , *HYMENOPTERA , *BRACONIDAE - Abstract
This is the most complete list of Aleiodes species of the subfamily Rogadinae from Vietnam, and of the total seventy five species of this genus reported, sixty three species of the subgenus Aleiodes, five of Arcaleiodes, three of Chelonorhogas, and four species of the genus Heterogamus. There are thirty species newly recorded from the Rogadinae fauna of Vietnam. The information on valid names, the published papers of the first record of Aleiodes species in Vietnam and the distribution of Aleiodes species were also provided. Additionally, there are three species listed with information about their hosts, being agricultural pests controlled to some degree by these parasitoids. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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33. Water resources and environment in and around Ho Chi Minh City, Vietnam.
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Duc, Hiep Nguyen and Truong, Truong Phuoc
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WATER supply , *WATER pollution , *WATER consumption - Abstract
Discusses the status of the water environment and water resources in Ho Chi Minh City, Vietnam in 2004. Water consumption in the city according to the Ho Chi Minh Service of Communication and Public Works; Sources of water pollution in the city; Efforts to improve the water quality and environment.
- Published
- 2003
34. Weather research and forecasting model tailored for regional airshed modelling in NSW.
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Prasad, Abhnil, Tzu-Chi Chang, Lisa, Fuchs, David, Duc, Hiep, Azzi, Merched, and Riley, Matthew
- Subjects
- *
METEOROLOGICAL research , *ATMOSPHERIC boundary layer , *WEATHER forecasting , *DUST storms , *ATMOSPHERIC models , *HEAT waves (Meteorology) - Abstract
A crucial aspect of regional air quality modelling is the accurate characterisation of local meteorology, as this plays a significant role in the transport and chemical transformation of pollution across a region. This study explores the potential of The Weather Research and Forecasting (WRF) model as an alternative meteorological model to support near-time air quality predictions for the NSW Greater Metropolitan Region (NSW GMR). We develop an optimal WRF configuration for the NSW GMR by downscaling the latest Bureau of Meteorology (BOM) Australian Community Climate and Earth-System Simulator (ACCESS) Numerical Weather Prediction (NWP) data using a three nested domain setup with resolutions of 12km, 4km and 1 km by varying physical parameterisations including two cumulus schemes, two planetary boundary layer schemes, two microphysical schemes, two compatible shortwave and longwave radiation schemes and a standard land surface model. Thus, a set of 16 experiments were executed and evaluated on different days involving high ozone days, bushfire smoke, dust storms and heatwaves. Each simulation was initialised at 12UTC with a forecast horizon of four days, including three hourly updates of boundary conditions. All simulations were evaluated with metrics including Mean Absolute Errors (MAE) and Index of Agreement (IOA) calculated over selected stations operated by NSW Department of Planning, Industry and Environment (NSW DPIE) and BOM for surface and vertical variables (temperature (T), relative humidity (RH), wind speed (WS)) including precipitation (PRECIP) and planetary boundary layer heights (PBLH). Overall, results showed that the best configuration produced acceptable agreements at the surface for T (IOA > 0.8), RH (IOA > 0.7) and WSP (IOA > 0.6). Errors in PBLH were elevated in the mid-boundary layer but was within 100m where vertical profiles of temperature and winds were well simulated. Similarly, experiments with double moment microphysical schemes were better in simulating precipitation. Other performance metrics for the experiments conducted under different case days will also be discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
35. Preliminary Results of Injury Surveillance at Viet Duc Hospital.
- Author
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Nguyen Duc Chinh, Coo Doc Lap, Nguyen Duc Hiep, Trinh Hong Son, Nguyen Lien Quyet, Nguyen Quang, Nguyen Thi Hong Tu, Iran Thi Ngoc Lan, Luong Mai Anh, and Judith L. Ladinsky
- Subjects
- *
WOUNDS & injuries , *ACCIDENT prevention , *MORTALITY , *DISEASES , *EPIDEMIOLOGY , *MEDICAL emergencies - Abstract
Purpose: Injurysurveillance, a key to injuryprevention, is the systematic collection, analysis, interpretation and dissemination of data on injury-related events for use in public health action to reduce morbidity and mortality and to improve health. The first injury surveillance was successfully implemented in a few pilot hospitals in Vietnam. Viet Duc Hospital, one of the leading centers of surgery and trauma in Vietnam, was one of these and has implemented an injury surveillance program. Materials and Methods: Data were collected from all cases of injuries treated and admitted to Viet Duc Hospital, including death data. The surveillance was conducted during the period from 26 March 2006 to 26 October 2006. Results: Data collected over 7 months in 2006 at Viet Duc Hospital showed 17,643 cases of injury treated in the emergency department, representing 70% of all emergencies. 989 patients died due to injury within 7 days, representing 5.6% of all injuries. Surveillance was conducted on 5,468 cases, in which men outnumbered women by a ratio of 3:1 and the highest proportion of patients were between 20 to 50 years of age. Patients referred from provinces accounted for 73% of cases. The highest categories of morbidity were among students and farmers who accounted for 22% and 25%. The largest numbers of injuries were to the head and face at 40%, second were to the extremities at 38%. Critical injuries accounted for only 2.6% of cases and serious injuries for only 3% based on Abbreviated Injury Scale (AIS) scaling. 30% received first aid at provincial hospitals and 23% at district hospitals. 38% of victims were transported by ambulance, 32% were accompanied by health workers. Traffic-related accidents accounted for 63% of all injuries, among which 74% of cases were from motorbike accidents. Motorbike drivers were injured in 70% of traffic cases. Only 5% of drivers were wearing helmets. Conclusions: In order to prevent injury as well as to reduce the mortality rate, data on injuries should be collected accurately and completely. Despite the challenges of implementing the first surveillance of injury in a hospital, the results are successful and informative in determining the epidemiology of injury, and providing accurate morbidity and mortality data. The value of hospital trauma registry as a major research tool is increasingly recognized because of its role in improving care of trauma patients and bringing about better resource utilization. Purpose: Injury surveillance, a key to injury prevention, is the systematic collection, analysis, interpretation and dissemination of data on injury-related events for use in public health action to reduce morbidity and mortality and to improve health. The first injury surveillance was successfully implemented in a few pilot hospitals in Vietnam. Viet Duc Hospital, one of the leading centers of surgery and trauma in Vietnam, was one of these and has implemented an injury surveillance program. Materials and Methods: Data were collected from all cases of injuries treated and admitted to Viet Duc Hospital, including death data. The surveillance was conducted during the period from 26 March 2006 to 26 October 2006. Results: Data collected over 7 months in 2006 at Viet Duc Hospital showed 17,643 cases of injury treated in the emergency department, representing 70% of all emergencies. 989 patients died due to injury within 7 days, representing 5.6% of all injuries. Surveillance was conducted on 5,468 cases, in which men outnumbered women by a ratio of 3:1 and the highest proportion of patients were between 20 to 50 years of age. Patients referred from provinces accounted for 73% of cases. The highest categories of morbidity were among students and farmers who accounted for 22% and 25%.… [ABSTRACT FROM AUTHOR]
- Published
- 2007
36. Dust Transport from Inland Australia and Its Impact on Air Quality and Health on the Eastern Coast of Australia during the February 2019 Dust Storm.
- Author
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Aragnou, Emilie, Watt, Sean, Nguyen Duc, Hiep, Cheeseman, Cassandra, Riley, Matthew, Leys, John, White, Stephen, Salter, David, Azzi, Merched, Tzu-Chi Chang, Lisa, Morgan, Geoffrey, and Hannigan, Ivan
- Subjects
- *
DUST storms , *AIR quality , *WEATHER forecasting , *AIR quality monitoring , *METEOROLOGICAL research , *GROUNDWATER monitoring , *FIREFIGHTING , *WILDFIRE prevention - Abstract
Dust storms originating from Central Australia and western New South Wales frequently cause high particle concentrations at many sites across New South Wales, both inland and along the coast. This study focussed on a dust storm event in February 2019 which affected air quality across the state as detected at many ambient monitoring stations in the Department of Planning, Industry and Environment (DPIE) air quality monitoring network. The WRF-Chem (Weather Research and Forecast Model—Chemistry) model is used to study the formation, dispersion and transport of dust across the state of New South Wales (NSW, Australia). Wildfires also happened in northern NSW at the same time of the dust storm in February 2019, and their emissions are taken into account in the WRF-Chem model by using Fire Inventory from NCAR (FINN) as emission input. The model performance is evaluated and is shown to predict fairly accurate the PM2.5 and PM10 concentration as compared to observation. The predicted PM2.5 concentration over New South Wales during 5 days from 11 to 15 February 2019 is then used to estimate the impact of the February 2019 dust storm event on three health endpoints, namely mortality, respiratory and cardiac disease hospitalisation rates. The results show that even though as the daily average of PM2.5 over some parts of the state, especially in western and north western NSW near the centre of the dust storm and wild fires, are very high (over 900 µg/m3), the population exposure is low due to the sparse population. Generally, the health impact is similar in order of magnitude to that caused by biomass burning events from wildfires or from hazardous reduction burnings (HRBs) near populous centres such as in Sydney in May 2016. One notable difference is the higher respiratory disease hospitalisation for this dust event (161) compared to the fire event (24). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
37. Major Source Contributions to Ambient PM2.5 and Exposures within the New South Wales Greater Metropolitan Region.
- Author
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Chang, Lisa T.-C., Scorgie, Yvonne, Duc, Hiep Nguyen, Monk, Khalia, Fuchs, David, and Trieu, Toan
- Subjects
- *
CARBONACEOUS aerosols , *PARTICULATE nitrate , *AIR quality management , *EMISSION inventories , *AMMONIUM sulfate , *SEA salt - Abstract
The coupled Conformal Cubic Atmospheric Model (CCAM) and Chemical Transport Model (CTM) (CCAM-CTM) was undertaken with eleven emission scenarios segregated from the 2008 New South Wales Greater Metropolitan Region (NSW GMR) Air Emission Inventory to predict major source contributions to ambient PM2.5 and exposure in the NSW GMR. Model results illustrate that populated areas in the NSW GMR are characterised with annual average PM2.5 of 6–7 µg/m3, while natural sources including biogenic emissions, sea salt and wind-blown dust contribute 2–4 µg/m3 to it. Summer and winter regional average PM2.5 ranges from 5.2–6.1 µg/m3 and 3.7–7.7 µg/m3 across Sydney East, Sydney Northwest, Sydney Southwest, Illawarra and Newcastle regions. Secondary inorganic aerosols (particulate nitrate, sulphate and ammonium) and sodium account for up to 23% and 18% of total PM2.5 mass in both summer and winter. The increase in elemental carbon (EC) mass from summer to winter is found across all regions but particularly remarkable in the Sydney East region. Among human-made sources, "wood heaters" is the first or second major source contributing to total PM2.5 and EC mass across Sydney in winter. "On-road mobile vehicles" is the top contributor to EC mass across regions, and it also has significant contributions to total PM2.5 mass, particulate nitrate and sulphate mass in the Sydney East region. "Power stations" is identified to be the third major contributor to the summer total PM2.5 mass across regions, and the first or second contributor to sulphate and ammonium mass in both summer and winter. "Non-road diesel and marine" plays a relatively important role in EC mass across regions except Illawarra. "Industry" is identified to be the first or second major contributor to sulphate and ammonium mass, and the second or third major contributor to total PM2.5 mass across regions. By multiplying modelled predictions with Australian Bureau of Statistics 1-km resolution gridded population data, the natural and human-made sources are found to contribute 60% (3.55 µg/m3) and 40% (2.41 µg/m3) to the population-weighted annual average PM2.5 (5.96 µg/m3). Major source groups "wood heaters", "industry", "on-road motor vehicles", "power stations" and "non-road diesel and marine" accounts for 31%, 26%, 19%, 17% and 6% of the total human-made sources contribution, respectively. The results in this study enhance the quantitative understanding of major source contributions to ambient PM2.5 and its major chemical components. A greater understanding of the contribution of the major sources to PM2.5 exposures is the basis for air quality management interventions aiming to deliver improved public health outcomes. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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38. Nematode morphometry and biomass in the Saigon River harbours in relation to antifouling contaminants.
- Author
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Ngo Xuan QUANG, Nguyen Thi My YEN, Tran Thanh THAI, Nguyen Ngoc CHAU, Nguyen Duc HIEP, SMOL, Nic, LINS, Lidia, and VANREUSEL, Ann
- Subjects
- *
NEMATODE morphology , *BIOCIDES , *OXIDATION-reduction reaction , *NEMATODE physiology - Abstract
Morphometry and biomass of nematode communities in different harbours of the Saigon River were investigated in the dry and wet seasons in relation to environmental variables such as total organic carbon, pH, conductivity, salinity and oxygen redox potential, in addition to concentrations of different butyltin compounds. The results indicated that nematodes in contaminated sediments from the Saigon River harbours were mainly characterised by slender morphotypes, whilst very few thin and stout nematodes were observed. Individual nematode biomass was generally low, especially in the wet season. There was no significant correlation between butyltin compounds and nematode morphometrics in the dry season but significant correlations were found for the wet season. Although significant correlations were observed for the wet season, the strong seasonal differences in nematode biomass spectra suggest a potential limitation in their use for environmental monitoring. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
39. The health benefits of reducing air pollution in Sydney, Australia.
- Author
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Broome, Richard A., Fann, Neal, Cristina, Tina J. Navin, Fulcher, Charles, Duc, Hiep, and Morgan, Geoffrey G.
- Subjects
- *
AIR pollution , *HEALTH , *PUBLIC health , *METROPOLITAN areas , *MEDICAL economics ,OZONE & the environment - Abstract
Among industrialised countries, fine particle (PM 2.5 ) and ozone levels in the Sydney metropolitan area of Australia are relatively low. Annual mean PM 2.5 levels have historically remained below 8 μg/m 3 while warm season (November–March) ozone levels occasionally exceed the Australian guideline value of 0.10 ppm (daily 1 h max). Yet, these levels are still below those seen in the United States and Europe. This analysis focuses on two related questions: (1) what is the public health burden associated with air pollution in Sydney; and (2) to what extent would reducing air pollution reduce the number of hospital admissions, premature deaths and number of years of life lost (YLL)? We addressed these questions by applying a damage function approach to Sydney population, health, PM 2.5 and ozone data for 2007 within the BenMAP-CE software tool to estimate health impacts and economic benefits. We found that 430 premature deaths (90% CI: 310–540) and 5800 YLL (95% CI: 3900–7600) are attributable to 2007 levels of PM 2.5 (about 2% of total deaths and 1.8% of YLL in 2007). We also estimate about 630 (95% CI: 410–840) respiratory and cardiovascular hospital admissions attributable to 2007 PM 2.5 and ozone exposures. Reducing air pollution levels by even a small amount will yield a range of health benefits. Reducing 2007 PM 2.5 exposure in Sydney by 10% would, over 10 years, result in about 650 (95% CI: 430–850) fewer premature deaths, a gain of 3500 (95% CI: 2300–4600) life-years and about 700 (95% CI: 450–930) fewer respiratory and cardiovascular hospital visits. These results suggest that substantial health benefits are attainable in Sydney with even modest reductions in air pollution. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
40. Evaluation of Regional Air Quality Models over Sydney, Australia: Part 2, Comparison of PM2.5 and Ozone.
- Author
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Guérette, Elise-Andrée, Chang, Lisa Tzu-Chi, Cope, Martin E., Duc, Hiep N., Emmerson, Kathryn M., Monk, Khalia, Rayner, Peter J., Scorgie, Yvonne, Silver, Jeremy D., Simmons, Jack, Trieu, Toan, Utembe, Steven R., Zhang, Yang, and Paton-Walsh, Clare
- Subjects
- *
AIR quality , *AIR quality standards , *OZONE , *PARTICULATE matter , *ATMOSPHERIC composition , *OZONE generators , *EMISSION control , *OZONESONDES - Abstract
Accurate air quality modelling is an essential tool, both for strategic assessment (regulation development for emission controls) and for short-term forecasting (enabling warnings to be issued to protect vulnerable members of society when the pollution levels are predicted to be high). Model intercomparison studies are a valuable support to this work, being useful for identifying any issues with air quality models, and benchmarking their performance against international standards, thereby increasing confidence in their predictions. This paper presents the results of a comparison study of six chemical transport models which have been used to simulate short-term hourly to 24 hourly concentrations of fine particulate matter less than and equal to 2.5 µm in diameter (PM2.5) and ozone (O3) for Sydney, Australia. Model performance was evaluated by comparison to air quality measurements made at 16 locations for O3 and 5 locations for PM2.5, during three time periods that coincided with major atmospheric composition measurement campaigns in the region. These major campaigns included daytime measurements of PM2.5 composition, and so model performance for particulate sulfate (SO42−), nitrate (NO3−), ammonium (NH4+) and elemental carbon (EC) was evaluated at one site per modelling period. Domain-wide performance of the models for hourly O3 was good, with models meeting benchmark criteria and reproducing the observed O3 production regime (based on the O3/NOx indicator) at 80% or more of the sites. Nevertheless, model performance was worse at high (and low) O3 percentiles. Domain-wide model performance for 24 h average PM2.5 was more variable, with a general tendency for the models to under-predict PM2.5 concentrations during the summer and over-predict PM2.5 concentrations in the autumn. The modelling intercomparison exercise has led to improvements in the implementation of these models for Sydney and has increased confidence in their skill at reproducing observed atmospheric composition. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
41. Evaluation of Regional Air Quality Models over Sydney and Australia: Part 1—Meteorological Model Comparison.
- Author
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Monk, Khalia, Guérette, Elise-Andrée, Paton-Walsh, Clare, Silver, Jeremy D., Emmerson, Kathryn M., Utembe, Steven R., Zhang, Yang, Griffiths, Alan D., Chang, Lisa T.-C., Duc, Hiep N., Trieu, Toan, Scorgie, Yvonne, and Cope, Martin E.
- Subjects
- *
METEOROLOGY , *ATMOSPHERIC models , *ATMOSPHERIC boundary layer , *AIR quality , *PHOTOCHEMICAL smog , *AUTOMATIC meteorological stations - Abstract
The ability of meteorological models to accurately characterise regional meteorology plays a crucial role in the performance of photochemical simulations of air pollution. As part of the research funded by the Australian government's Department of the Environment Clean Air and Urban Landscape hub, this study set out to complete an intercomparison of air quality models over the Sydney region. This intercomparison would test existing modelling capabilities, identify any problems and provide the necessary validation of models in the region. The first component of the intercomparison study was to assess the ability of the models to reproduce meteorological observations, since it is a significant driver of air quality. To evaluate the meteorological component of these air quality modelling systems, seven different simulations based on varying configurations of inputs, integrations and physical parameterizations of two meteorological models (the Weather Research and Forecasting (WRF) and Conformal Cubic Atmospheric Model (CCAM)) were examined. The modelling was conducted for three periods coinciding with comprehensive air quality measurement campaigns (the Sydney Particle Studies (SPS) 1 and 2 and the Measurement of Urban, Marine and Biogenic Air (MUMBA)). The analysis focuses on meteorological variables (temperature, mixing ratio of water, wind (via wind speed and zonal wind components), precipitation and planetary boundary layer height), that are relevant to air quality. The surface meteorology simulations were evaluated against observations from seven Bureau of Meteorology (BoM) Automatic Weather Stations through composite diurnal plots, Taylor plots and paired mean bias plots. Simulated vertical profiles of temperature, mixing ratio of water and wind (via wind speed and zonal wind components) were assessed through comparison with radiosonde data from the Sydney Airport BoM site. The statistical comparisons with observations identified systematic overestimations of wind speeds that were more pronounced overnight. The temperature was well simulated, with biases generally between ±2 °C and the largest biases seen overnight (up to 4 °C). The models tend to have a drier lower atmosphere than observed, implying that better representations of soil moisture and surface moisture fluxes would improve the subsequent air quality simulations. On average the models captured local-scale meteorological features, like the sea breeze, which is a critical feature driving ozone formation in the Sydney Basin. The overall performance and model biases were generally within the recommended benchmark values (e.g., ±1 °C mean bias in temperature, ±1 g/kg mean bias of water vapour mixing ratio and ±1.5 m s−1 mean bias of wind speed) except at either end of the scale, where the bias tends to be larger. The model biases reported here are similar to those seen in other model intercomparisons. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
42. Antitumor Activity of DFX117 by Dual Inhibition of c-Met and PI3Kα in Non-Small Cell Lung Cancer.
- Author
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Fan, Yanhua, Ding, Huaiwei, Kim, Donghwa, Bach, Duc-Hiep, Hong, Ji-Young, Xu, Yongnan, and Lee, Sang Kook
- Subjects
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ANIMAL experimentation , *APOPTOSIS , *BIOLOGICAL models , *CELL cycle , *CELL lines , *CHALONES , *DRUG delivery systems , *LUNG cancer , *MICE , *MOLECULAR structure , *GENETIC mutation , *PHOSPHOTRANSFERASES , *TREATMENT effectiveness , *IN vitro studies , *IN vivo studies , *CHEMICAL inhibitors - Abstract
Aberrant activation of hepatocyte growth factor (HGF)/c-Met signaling pathway caused by gene amplification or mutation plays an important role in tumorigenesis. Therefore, c-Met is considered as an attractive target for cancer therapy and c-Met inhibitors have been developed with great interests. However, cancers treated with c-Met inhibitors inevitably develop resistance commonly caused by the activation of PI3K/Akt signal transduction pathway. Therefore, the combination of c-Met and PI3Kα inhibitors showed synergistic activities, especially, in c-Met hyperactivated and PIK3CA-mutated cells. In our previous study, we rationally designed and synthesized DFX117(6-(5-(2,4-difluorophenylsulfonamido)-6-methoxypyridin-3-yl)-N-(2-morpholinoethyl) imidazo[1,2-a]pyridine-3-carboxamide) as a novel PI3Kα selective inhibitor. Herein, the antitumor activity and underlying mechanisms of DFX117 against non-small cell lung cancer (NSCLC) cells were evaluated in both in vitro and in vivo animal models. Concurrent targeted c-Met and PI3Kα by DFX117 dose-dependent inhibited the cell growth of H1975 cells (PIK3CA mutation and c-Met amplification) and A549 cells (KRAS mutation). DFX117 subsequently induced G0/G1 cell cycle arrest and apoptosis. These data highlight the significant potential of DFX117 as a feasible and efficacious agent for the treatment of NSCLC patients. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
43. The Role of Platelets in the Tumor-Microenvironment and the Drug Resistance of Cancer Cells.
- Author
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Huong, Phung Thanh, Nguyen, Lap Thi, Nguyen, Xuan-Bac, Lee, Sang Kook, and Bach, Duc-Hiep
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BLOOD platelets , *CELL lines , *TUMOR treatment , *CELL physiology , *DRUG resistance in cancer cells , *METASTASIS , *NEOVASCULARIZATION , *PLATELET-derived growth factor , *PHYSIOLOGY - Abstract
Besides the critical functions in hemostasis, thrombosis and the wounding process, platelets have been increasingly identified as active players in various processes in tumorigenesis, including angiogenesis and metastasis. Once activated, platelets can release bioactive contents such as lipids, microRNAs, and growth factors into the bloodstream, subsequently enhancing the platelet–cancer interaction and stimulating cancer metastasis and angiogenesis. The mechanisms of treatment failure of chemotherapeutic drugs have been investigated to be associated with platelets. Therefore, understanding how platelets contribute to the tumor microenvironment may potentially identify strategies to suppress cancer angiogenesis, metastasis, and drug resistance. Herein, we present a review of recent investigations on the role of platelets in the tumor-microenvironment including angiogenesis, and metastasis, as well as targeting platelets for cancer treatment, especially in drug resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. Skill-Testing Chemical Transport Models across Contrasting Atmospheric Mixing States Using Radon-222.
- Author
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Chambers, Scott D., Guérette, Elise-Andree, Monk, Khalia, Griffiths, Alan D., Zhang, Yang, Duc, Hiep, Cope, Martin, Emmerson, Kathryn M., Chang, Lisa T., Silver, Jeremy D., Utembe, Steven, Crawford, Jagoda, Williams, Alastair G., and Keywood, Melita
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ATMOSPHERIC aerosols , *RADON , *CHEMICAL reactions , *SIMULATION methods & models , *NANOPARTICLES - Abstract
We propose a new technique to prepare statistically-robust benchmarking data for evaluating chemical transport model meteorology and air quality parameters within the urban boundary layer. The approach employs atmospheric class-typing, using nocturnal radon measurements to assign atmospheric mixing classes, and can be applied temporally (across the diurnal cycle), or spatially (to create angular distributions of pollutants as a top-down constraint on emissions inventories). In this study only a short (<1-month) campaign is used, but grouping of the relative mixing classes based on nocturnal mean radon concentrations can be adjusted according to dataset length (i.e., number of days per category), or desired range of within-class variability. Calculating hourly distributions of observed and simulated values across diurnal composites of each class-type helps to: (i) bridge the gap between scales of simulation and observation, (ii) represent the variability associated with spatial and temporal heterogeneity of sources and meteorology without being confused by it, and (iii) provide an objective way to group results over whole diurnal cycles that separates 'natural complicating factors' (synoptic non-stationarity, rainfall, mesoscale motions, extreme stability, etc.) from problems related to parameterizations, or between-model differences. We demonstrate the utility of this technique using output from a suite of seven contemporary regional forecast and chemical transport models. Meteorological model skill varied across the diurnal cycle for all models, with an additional dependence on the atmospheric mixing class that varied between models. From an air quality perspective, model skill regarding the duration and magnitude of morning and evening "rush hour" pollution events varied strongly as a function of mixing class. Model skill was typically the lowest when public exposure would have been the highest, which has important implications for assessing potential health risks in new and rapidly evolving urban regions, and also for prioritizing the areas of model improvement for future applications. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
45. Hot Summers: Effect of Extreme Temperatures on Ozone in Sydney, Australia.
- Author
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Utembe, Steven R., Rayner, Peter J., Silver, Jeremy D., Guérette, Elise-Andree, Fisher, Jenny A., Emmerson, Kathryn M., Cope, Martin, Paton-Walsh, Clare, Griffiths, Alan D., Duc, Hiep, Monk, Khalia, and Scorgie, Yvonne
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HOT weather conditions , *ATMOSPHERIC ozone , *EMISSIONS (Air pollution) , *AIR quality , *ATMOSPHERIC aerosols - Abstract
Poor air quality is often associated with hot weather, but the quantitative attribution of high temperatures on air quality remains unclear. In this study, the effect of elevated temperatures on air quality is investigated in Greater Sydney using January 2013, a period of extreme heat during which temperatures at times exceeded 40 °C, as a case study. Using observations from 17 measurement sites and the Weather Research and Forecasting Chemistry (WRF-Chem) model, we analyse the effect of elevated temperatures on ozone in Sydney by running a number of sensitivity studies in which: (1) the model is run with biogenic emissions generated by MEGAN and separately run with monthly average Model of Emissions of Gases and Aerosols from Nature (MEGAN) biogenic emissions (for January 2013); (2) the model results from the standard run are compared with those in which average temperatures (for January 2013) are only applied to the chemistry; (3) the model is run using both averaged biogenic emissions and temperatures; and (4 and 5) the model is run with half and zero biogenic emissions. The results show that the impact on simulated ozone through the effect of temperature on reaction rates is similar to the impact via the effect of temperature on biogenic emissions and the relative impacts are largely additive when compared to the run in which both are averaged. When averaged across 17 sites in Greater Sydney, the differences between ozone simulated under standard and averaged model conditions are as high as 16 ppbv. Removing biogenic emissions in the model has the effect of removing all simulated ozone episodes during extreme heat periods, highlighting the important role of biogenic emissions in Australia, where Eucalypts are a key biogenic source. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
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