5,379 research outputs found
Improvement on PM-10 Forecast by Using Hybrid ARIMAX and Neural Networks Model for the Summer Season in Chiang Mai
No full textAbstractSince the air monitoring stations do not provide the relation between other toxic gas and meteorological parameters with the particulate matter up to 10 micrometer or PM-10. The influence of meteorological as well as correlation with other toxic gas is investigated and used them to forecast PM-10 in the case of Chiang Mai province of Thailand. In this paper an attempt to develop hybrid models of an Autoregressive Integrated Moving Average (ARIMA) model with other exogenous variables (ARIMAX) and Neural Networks (NNs), the two hybrid models, i.e. hybrid ARIMAX-NNs model and hybrid NNs-ARIMAX model were implemented to forecast PM-10 for highly season during January-April of Chiang Mai Province. Simulation results of hybrid model are compared with the results of ARIMA, ARIMAX and NNs model. The experimental results demonstrated that the hybrid NNs-ARIMAX model outperformed best over the hybrid ARIMAX-NNs model, ARIMAX model, NNs model, and ARIMA model respectively. In this case study and maybe other cases, it has proved that the NNs model should be priori captured and filtered the non-stationary non-linear component while the fully linearly stationary residuals were accurately predicted by ARIMAX model later
Disseminated tuberculosis presenting as multiple hepatosplenic microabscesses and pancytopenia in a teenage boy
No full textToxicity and Chemical Composition of Airborne Particulate Matter in Ambient Air of Tambon Don Kaew, Mae Rim District, Chiang Mai Province
No full textการวิจัยครั้งนี้มีวัตถุประสงค์เพื่อศึกษาฤทธิ์ความเป็นพิษต่อยีนปนเปื้อนและตรวจวิเคราะห์หาองค์ประกอบทางเคมีในอนุภาคฝุ่นขนาดเล็กในตัวอย่างอากาศของพื้นที่ตำบลดอนแก้ว อำเภอแม่ริม จังหวัดเชียงใหม่ ระหว่างเดือนธันวาคม 2550 ถึง เดือน สิงหาคม 2551 ทำการเก็บอนุภาคฝุ่นขนาดเล็กขนาด 10 ไมโครเมตร ด้วยกระดาษกรองโดยใช้เครื่องมือที่ใช้อัตราการดูดอากาศสูง ทั้งหมด 4 จุด ได้แก่ เส้นทางจราจร พื้นที่การเกษตร เตาเผาขยะ และย่านที่พักอาศัย และทำการตรวจวัดองค์ประกอบทางเคมีโดยตรวจวิเคราะห์หา ก๊าซมีเทน ก๊าซนอนมีเทน ก๊าซไฮโดรคาร์บอน ทำการสกัดแผ่นกรองเก็บอนุภาคฝุ่นขนาดเล็กด้วยสารตัวทำละลายไดคลอโรมีเทน โดยใช้เครื่องแรงสั่นสะเทือนด้วยความถี่สูง แล้วนำสารสกัดไปทดสอบฤทธิ์การก่อกลายพันธุ์ต่อเชื้อแบคทีเรียสัลโมเนลลา ธัยฟิมิวเรียม สายพันธุ์ TA98 และ TA100 ในภาวะที่มีหรือไม่มีการกระตุ้นด้วยเอนซัยม์ ผลการวิจัยพบว่าค่าเฉลี่ยของอนุภาคฝุ่นขนาดเล็ก(พีเอ็ม10) โดยน้ำหนัก อยู่ระหว่าง 14.0 – 47.0 ไมโครกรัมต่อลูกบาศก์เมตร ซึ่งมีระดับต่ำกว่าค่ามาตรฐาน 120 ไมโครกรัมต่อลูกบาศก์เมตร ตามมาตรฐานคุณภาพอากาศในบรรยากาศทั่วไป ปริมาณก๊าซมีเทน ก๊าซนอนมีเทน ก๊าซไฮโดรคาร์บอน มีค่า 1.96-2.06, 0.35-1.42, และ 2.34-3.38 หนึ่งส่วนในล้านส่วน ตามลำดับ และฤทธิ์การก่อกลายพันธุ์ต่อเชื้อแบคทีเรียสัลโมเนลลา ธัยฟิมิวเรียม สายพันธุ์ TA98 และ TA100 ในภาวะที่มีหรือไม่มีการกระตุ้นด้วยเอนซัยม์ พบว่ามีผลต่อการกลายพันธุ์ของแบคทีเรียดังกล่าวทั้งแบบโดยตรงและโดยผ่านเอนซัยม์ นอกจากนี้พบว่าฤทธิ์การก่อการกลายพันธุ์ของอนุภาคฝุ่นขนาดเล็ก (พีเอ็ม10) ไม่มีความแตกต่างกันที่เก็บตัวอย่างมาจากแหล่งกำเนิดในช่วงเวลาเดียวกัน ซึ่งอาจเนื่องมาจากแหล่งกำเนิดของอนุภาคฝุ่นขนาดเล็กเป็นแหล่งเดียวกัน อนุภาคฝุ่นขนาดเล็กไม่มีผลกระทบต่อสุขภาพของประชาชนในพื้นที่ตำบลดอนแก้ว อำเภอแม่ริม จังหวัดเชียงใหม่ แต่อาจมีผลกระทบต่อผู้ป่วยโรคระบบทางเดินหายใจ องค์การบริหารส่วนตำบลดอนแก้วนับได้ว่าเป็นองค์การปกครองส่วนท้องถิ่นต้นแบบ ในการแก้ไขปัญหามลพิษทางอากาศและสร้างสุขภาวะแวดล้อมที่ดีให้กับประชาชนในพื้นที่ตำบลดอนแก้ว อำเภอแม่ริม จังหวัดเชียงใหม่Toxicity and chemical composition of cirborne particulate matter in ambient air of Tambon Don Kaew, Mae Rim District, Chiang Mai Province have been carried out during the period between December 2007 and August 2008. PM 10 samples were collected on filters, with the use of High volume air sampler and hydrocarbons (CH4, NMHC, and THC) were monitored of four sampling sites; traffic source, agricultural source, incinerator source, and residential area. Twenty-four hour air particulate matter samples were extracted with dichloromethane by ultrasonication. The organic extracts of PM 10 were tested by short-term mutagenicity bioassays using Salmonella tester strains TA98 and TA100, with and without metabolic activation (S9). The daily levels of PM 10 mass concentration of Tambon Don Kaew ranged from 14.0 to 47.0 g/m3 which lower than the Pollution Control Department (PCD), PM 10, the 24 h standard of 120 g/m3 and the concentration of methane, non-methane, and total hydrocarbon ranged from 1.96-2.06, 0.35-1.42, และ 2.34-3.38 ppm, respectively. The study showed that direct mutagenicity with TA98 and TA100 strains in airborne particulate matter extracts was detected in all samples. The mutagenicities became positive, and were higher, in the presence of enzyme activation (S9 mix). In conclusions, the results of the PM 10 studies presented here have implications for future research as well as efforts to regulate particulate matter and to improve the health of Tambon Don Kaew residents.สำนักงานคณะกรรมการวิจัยแห่งชาต
Short-term effects of air pollution and temperature on daily morbidity in Chiang Mai Thailand
Full text linkAir pollution is associated with mortality and morbidity worldwide. Hot and cold temperature is also related to increased deaths and possibly hospital visits and admissions in many settings. Climate change is anticipated to pose increasing risks of deaths and illnesses associated with air pollution and temperature variations, particularly in developing world. To date, research studies about health effects of air pollution and temperature have been conducted in developed countries with cool climate more than in developing countries with subtropical or tropical climate. Furthermore, studies to identify susceptible populations are still limited. This study aims to investigate heath effects of air pollution and temperature and to identify people who are more susceptible to air pollution and temperature in a developing, tropical country, Thailand.
A regression analysis of retrospective time series data was employed to assess the shortterm effects of air pollution and temperature on daily out-patient visits and hospital admissions in Chiang Mai, Thailand, from October 2002 to September 2006. Generalised negative binomial regression was used to model the relationships between the exposure and health outcomes, controlling for seasonal patterns and other possible potential confounders. Lag effects up to 4 days for air pollution, and up to 13 days for temperature were considered. Effect modification by age, sex, occupation, season, and previous out-patient visits before admissions were also examined.
There were positive, but not significant, effects of air pollution for some pollutants (particularly for S02), with notably larger effect sizes compared to previous studies in Western countries. There was evidence of hot temperature effects (though wide confidence intervals), with an increase in diabetic visits of 26.3% (95% Cl, 7.1% to 49.0%), and in circulatory visits of 19.2% (95% Cl, 7.0% to 32.8%) for each 1°C increase in temperature above 29°C. There was a rise of both the visits (3.7% increase, 95% Cl, 1.5% to 5.9%) and admissions (5.8% increase, 95% Cl, 2.3% to 9.3%) due to intestinal infectious disease for each 1°C increase across the whole temperature range. Despite no statistically significant differences between subgroups, air pollution effects were stronger in the elderly, females and manual workers, whereas temperature effects were stronger in the elderly, male and unemployed people.
This study suggests that while there was little evidence of air pollution effects, there was significant evidence of high temperature effects on daily morbidity in Chiang Mai. The elderly seemed to be more vulnerable to the daily changes of both air pollution and temperature
Vitamin D3 regulates PM-driven primary human neutrophil inflammatory responses
No full textAbstract Recent evidence has demonstrated that both acute and chronic exposure to particulate air pollution are risk factors for respiratory tract infections and increased mortality from sepsis. There is therefore an urgent need to establish the impact of ambient particulate matter (PM) on innate immune cells and to establish potential strategies to mitigate against adverse effects. PM has previously been reported to have potential adverse effects on neutrophil function. In the present study, we investigated the impact of standard urban PM (SRM1648a, NIST) and PM2.5 collected from Chiang Mai, Thailand, on human peripheral blood neutrophil functions, including LPS-induced migration, IL-8 production, and bacterial killing. Both NIST and the PM2.5, being collected in Chiang Mai, Thailand, increased IL-8 production, but reduced CXCR2 expression and migration of human primary neutrophils stimulated with Escherichia coli LPS. Moreover, PM-pretreated neutrophils from vitamin D-insufficient participants showed reduced E. coli-killing activity. Furthermore, in vitro vitamin D3 supplementation attenuated IL-8 production and improved bacterial killing by cells from vitamin D-insufficient participants. Our findings suggest that provision of vitamin D to individuals with insufficiency may attenuate adverse acute neutrophilic responses to ambient PM
The Elemental Characteristics and Human Health Risk of PM(2.5) during Haze Episode and Non-Haze Episode in Chiang Rai Province, Thailand
No full textFine particle matter (PM(2.5)) was directly related to seasonal weather, and has become the influencing factor of air quality that is harmful for human health in Chiang Rai province. The aims were determining the elemental composition in PM(2.5) and human health risk in haze (March 2021) and non-haze episodes (July–August 2021). Nine elements in PM(2.5) were measured by using an Atomic Absorption Spectrophotometer, and an enrichment factor was used to identify the emission source. The results showed that the average concentration of PM(2.5) was 63.07 μg/m(3) in haze episodes, and 25.00 μg/m(3) in a non-haze episode. The maximum concentration was 116.7 μg/m(3) in March. The majority of elements originated from anthropogenic sources. In haze episodes, PM(2.5) mean concentration was approximately 4.2 times that of the WHO guidelines (15 μg/m(3) 24 h), and 1.3 times that of the Thai Ambient Air Quality Standard (50 μg/m(3)). The analysis of backward air mass trajectory showed that transboundary and local sources significantly influenced PM(2.5) at the monitoring site in the sampling period. In the health risk assessment, the non-carcinogenic risk of Cd was the highest, with a Hazard Quotient (HQ) of 0.048, and the cancer risk of Cr was classified as the highest cancer risk, with the values of 1.29 × 10(−5), higher than the minimum acceptable level
Frequent nuclear expression of ]-catenin protein but rare ]-catenin mutation in pulmonary sclerosing hemangioma.
No full textMobile Technologies and New Narratives of the Self
No full textTed Chiang is the author of "Stories of Your Life and Others" and "The Lifecycle of Software Objects", and this year’s author for Project One. He was born and raised in Port Jefferson, New York, and attended Brown University, where he received a degree in computer science. His work has received the John W. Campbell Award, four Nebula Awards, four Hugo Awards, four Locus Awards, a Theodore Sturgeon Memorial Award, a Sidewise Award, and a British Science Fiction Association Award. He lives outside of Seattle, Washington.Presented on September 30, 2014 at 5:00 pm in the Student Center Ballroom.Runtime: 81:27 minutesIn the very near future it will become practical for a wearable computer to record every
moment of your waking life. There's an ongoing discussion about the etiquette
of devices like Google Glass, but there are also long-term implications that
are completely separate from questions of privacy. As we make greater use of
mobile computing devices, our cognitive habits are likely to shift away from
relying on our own recollection of events and toward consulting digital
video. Will this change the way we understand our pasts
In vitro assessment of the pulmonary toxicity of particulate matter emitted during haze events in Chiang Mai, Thailand via investigation of macrophage responses
No full textChiang Mai (Thailand) experiences severe haze pollution in the dry season (December–April) each year mainly due to local and regional biomass burning (e.g. of agricultural land). A major component of the haze is airborne particulate matter (PM). During haze events, biomass burning is likely to be the dominant source of PM emissions, and at other times emissions from traffic dominate. The hazard of traffic derived PM has been extensively investigated previously but there are uncertainties regarding the toxicity of PM emitted from biomass burning. The toxicity of PM10 samples collected during and after haze events in Chiang Mai in 2020 was compared in vitro in J774.1 macrophages as they are responsible for the clearance of inhaled particles. Diesel exhaust particles and ultrafine carbon black were included as benchmark particles as they have been commonly used as a surrogate for PM. Cytotoxicity was evaluated 24 h post exposure at concentrations of 3.9–125 µg ml−1. Cytokine production (tumour necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1β, macrophage inflammatory protein (MIP-2)) was assessed and cell morphology visualised using light and scanning electron microscopy. The hydrodynamic diameter, zeta potential and endotoxin content of all particles was assessed as well as the metal content of PM samples. All particles induced a concentration dependent decrease in cell viability and increased TNF-α and MIP-2 production. Only PM samples stimulated IL-6 production and only non-haze PM caused IL-1β production. No change in IL-10 production was detected for any particle. PM samples and DEP caused vacuole formation in cells. The concentrations of endotoxin and metals were highest in non-haze PM, which may explain why it induced the greatest inflammatory response. As non-haze PM was more toxic than haze PM, our results indicate that the source of PM emissions can influence its toxic potency and more specifically, that PM emitted from biomass burning may be less toxic than PM emitted from traffic
Energy transfers in small-scale and large-scale dynamos
No full textWe study energy transfers during magnetic energy growth in small-scale and large-scale dynamos. We perform direct numerical simulations for magnetic Prandtl number Pm =20 and 0.2 in a periodic box on 1024^3 grid. Energy fluxes and shell-to-shell energy transfers indicate that in small-scale dynamo for Pm =20, the magnetic energy growth takes place due to a non-local energy transfer from large-scale velocity field to small-scale magnetic field. On the other hand, in large-scale dynamo for Pm =0.2, local energy transfers from large-scale velocity field to large-scale magnetic field takes place
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