245 research outputs found
Extraction of active, contaminant degrading enzymes from soil
Soil microorganisms play critical roles in the degradation of micro-and nano-pollutants, and the corresponding proteins and enzymes play roles in pollutant recognition, transportation, and degradation. Our ability to study these pathways from soil samples is often complicated by the complex processes involved in extracting proteins from soil matrices. This study aimed to develop a new protein soil extraction protocol that yielded active, intracellular enzymes from the perchlorate degradation pathway, particularly perchlorate reductase. An indirect method, which focused on first separating the cells from the soil matrix, followed by cell lysis and enzyme extraction, was evaluated. The optimized indirect method achieved a final extraction efficiency of the active enzyme and total protein of 15.7 % and 3.3 %, respectively. The final step of separating enzymes from residual soil components resulted in the highest activity and protein losses of 67.7 % ± 14.8 % and 91.8 % ± 1.8 %, respectively. Five buffers, each at different concentrations (0.01 M, 0.05 M, and 0.1 M), were tested to enhance enzyme extraction efficiency. The best extractant requires careful consideration between the highest activity and the quality of the recovered enzymes. Coextraction of humic substances could be minimized by using 0.1 M as compared to 0.01 M and 0.05 M of sodium pyrophosphate; however, this resulted in less recovered activity compared to lower extractant concentrations
Flexural-strengthening efficiency of cfrp sheets for unbonded post-tensioned concrete T-beams
There has been a limited number of studies about the flexural behavior of unbonded post-tensioned concrete (UPC) beams strengthened with carbon fibre reinforced polymer (CFRP) and these studies have not systematically examined the effect of CFRP sheets on the tendon strain as well as the strengthening efficiency. Moreover, current design guides for the FRP strengthening techniques have not provided any design procedure for UPC structures. This study, thus, investigates the influence of CFRP sheet ratio on the flexural behavior of CFRP-strengthened UPC T-beams and quantifies its effect upon tendon behavior in this kind of UPC beams. The testing program consisted of nine large-scale UPC T-beams strengthened by different layers of CFRP sheets with or without CFRP U-wrapped anchors. The experimental results have shown that the use of CFRP sheets and CFRP U-wrapped anchors significantly affected the tendon strain. The FRP reinforcement ratio governed the flexural capacity, the crack width, the mid-span displacement, and the ductility of the beams in which the strengthening efficiency reduces with the increased number of CFRP layers. The configuration of the CFRP U-wrapped anchors affected the strain of the CFRP sheets, the failure mode and thus the beam behavior. In addition, semi-empirical equations were proposed to estimate the actual strain of unbonded tendons in which the effect of the CFRP sheets and CFRP U-wrapped anchors have been taken into consideration. The proposed equations, which are simple to use, yield reliable predictions with a small variation
Forager and farmer evolutionary adaptations to malaria evidenced by 7000 years of thalassemia in Southeast Asia
Acknowledgements We would like to thank Dr. Ngo Anh Son, Mr. Bui Van Khanh and Ms. Nellissa Ling for their assistance with the radiographs. We are grateful to Dr. Dr. Nguyen Gia Doi for permission to extract histological samples. This work was supported by a National Geographic Early Career Grant (EC-54332R-18);Royal Society of New Zealand Skinner Fund Grant; University of Otago Doctoral Scholarship; Australian Research Council DP110101097 and FT120100299. Histologicalprocessing was funded by the Australian Research Council (DE190100068).Peer reviewedPublisher PD
Forager and farmer evolutionary adaptations to malaria evidenced by 7000 years of thalassemia in Southeast Asia
Thalassemias are inherited blood disorders that are found in high prevalences in the Mediterranean, Southeast Asia and the Pacific. These diseases provide varying levels of resistance to malaria and are proposed to have emerged as an adaptive response to malaria in these regions. The transition to agriculture in the Holocene has been suggested to have influenced the selection for thalassemia in the Mediterranean as land clearance for farming encouraged interaction between Anopheles mosquitos, the vectors for malaria, and human groups. Here we document macroscopic and microscopic skeletal evidence for the presence of thalassemia in both hunter-gatherer (Con Co Ngua) and early agricultural (Man Bac) populations in northern Vietnam. Firstly, our findings demonstrate that thalassemia emerged prior to the transition to agriculture in Mainland Southeast Asia, from at least the early seventh millennium BP, contradicting a long-held assumption that agriculture was the main driver for an increase in malaria in Southeast Asia. Secondly, we describe evidence for significant malarial burden in the region during early agriculture. We argue that the introduction of farming into the region was not the initial driver of the selection for thalassemia, as it may have been in other regions of the world
СИСТЕМА И АЛГОРИТМ ИНТЕЛЛЕКТУАЛЬНОЙ ОБРАБОТКИ И АНАЛИЗА БИОМЕДИЦИНСКИХ СИГНАЛОВ В СИСТЕМАХ УДАЛЕННОГО МОНИТОРИНГА СОСТОЯНИЯ ЗДОРОВЬЯ ЧЕЛОВЕКА
Continuous and steady running of health status remote monitoring systems is essential not to omit episodes of acute exacerbation of chronic disease. Running time of such systems is largely determined by performance capabilities of the patient's wearable system elements. To ensure its long-term operation and efficient performance, the monitoring system must have multilayered structure with the elements realizing recording and picking off biomedical signals, signal processing and analysis, estimation of patient current condition, dynamics of the disease and its prognosis. For this purpose, it is necessary to use smart monitoring algorithms. A specific feature of such algorithms is change of the number of channels used for biomedical signal recording and processing according to the change of patient’s condition. To detect the exacerbation first symptoms by means of the patient's wearable computer, additional channels are activated for recording biomedical signals used to evaluate the expanded complex of diagnostically significant parameters of the disease and their integration when specifying the patient's condition. The system and intelligent monitoring algorithm is tested with the use of heart rate remote control and atrial fibrillation episode detection system. The testing results of the developed system and algorithm are discussed.Непрерывная продолжительная работа систем мониторинга имеет большое значение для исключения пропуска эпизодов обострения заболевания. В системах удаленного мониторинга продолжительность непрерывной работы определяется возможностями носимых пациентом устройств. Они предназначены для съема и регистрации комплекса биомедицинских сигналов, предварительной обработки и анализа сигналов и данных.Цель настоящей статьи – разработка алгоритма интеллектуального мониторинга состояния здоровья. Он обеспечивает эффективное использование вычислительных и энергетических ресурсов носимых устройств пациента, снижение тока потребления, увеличение автономности его работы. Для решения проблемы используется методология теории интеллектуальных измерений. Она заключается в изменении интеллектуальным элементом системы количества используемых измерительных каналов, методов и алгоритмов измерений и обработки сигналов в зависимости от изменения состояния объекта измерений.Для реализации алгоритма интеллектуального мониторинга состояния здоровья система должна иметь многоуровневую структуру. Носимая система должна состоять из устройства пациента, предназначенного для регистрации комплекса биомедицинских сигналов, и носимого компьютера пациента, предназначенного для обработки и анализа сигналов, контроля текущего состояния пациента. Алгоритм интеллектуального мониторинга заключается в следующем. Фоновый режим устанавливается, когда состояние пациента соответствует состоянию нормы. В этом режиме оцениваются не более двух показателей, наиболее значимых для диагностики, и контролируется состояние нормы. Режим активного мониторинга устанавливается, когда контролируемые в фоновом режиме параметры выходят за границы нормы. В этом режиме активируются дополнительные каналы регистрации биомедицинских сигналов, оценивается расширенный комплекс значимых для диагностики показателей. Экспериментальная апробация системы и алгоритма интеллектуального мониторинга была проведена с использованием системы удаленного мониторинга сердечного ритма и эпизодов фибрилляции предсердий. Результаты апробации показали целесообразность и эффективность использования предложенной структуры и алгоритма мониторинга
Aligning assessment with the needs of work-integrated learning: the challenges of authentic assessment in a complex context
Work-integrated learning (WIL) is a feature of university courses, both in professional areas, where it is commonplace, but also across many different disciplines. Assessment of WIL can be complex as it involves parties and settings external to the university, and it can be problematic because of difficulties in aligning learning activities during placements with what is or can be assessed by the university. This paper explores the relationship between students’ placement experiences and accompanying assessments in contexts where activities are tightly coupled with the curriculum, and in those where it is not. It draws on a qualitative analysis of student interviews and drawings by the interviewees of their WIL experiences, supplemented with analysis of unit guides. Our findings highlight that students’ perceptions of authenticity of assessment were undermined by misalignments between the student, university and industry. Assessment authenticity was perceived by students as based on alignment between their current and future selves in the assessment process, involvement of industry supervisors and relevance of placement activities to assessment activities. The paper discusses the complexity of coordination of educational activities with external partners, especially when one party drives assessment. It then suggests a reframing of WIL assessment to promote alignment and authenticity
Self-reported use of tobacco products in nine rural INDEPTH Health and Demographic Surveillance Systems in Asia
BACKGROUND: Tobacco use is the most preventable cause of premature death and disability. Even though tobacco use is common in many Asian countries, reliable and comparable data on the burden imposed by tobacco use in this region are sparse, and surveillance systems to track trends are in their infancy. OBJECTIVE: To assess and compare the prevalence of tobacco use and its associated factors in nine selected rural sites in five Asian countries. METHODS: Tobacco use among 9,208 men and 9,221 women aged 25-64 years in nine Health and Demographic Surveillance System (HDSS) sites in five Asian countries of the INDEPTH Network were examined in 2005 as part of a broader survey of the major chronic non-communicable disease risk factors. All sites used a standardised protocol based on the WHO STEPS approach to risk factor surveillance; expanded questions of local relevance, including chewing tobacco, were also included. Multivariable logistic regression was used to assess demographic factors associated with tobacco use. RESULTS: Tobacco use, whether smoked or chewed, was common across all sites with some notable variations. More than 50% of men smoked daily; this applied to almost all age groups. Few women smoked daily in any of the sites. However, women were more likely to chew tobacco than men in all sites except Vadu in India. Tobacco use in men began in late adolescence in most of the sites and the number of cigarettes smoked daily ranged from three to 15. Use of both forms of tobacco, smoked and chewed, was associated with age, gender and education. Men were more likely to smoke compared to women, smoking increased with age in the four sites in Bangladesh but not in other sites and with low level of education in all the sites. CONCLUSION: The prevalence of tobacco use, regardless of the type of tobacco, was high among men in all of these rural populations with tobacco use started during adolescence in all HDSS sites. Innovative communication strategies for behaviour change targeting adolescents in schools and adult men and women at work or at home, may create a mass awareness about adverse health consequences of tobacco smoking or chewing tobacco. Such efforts, to be effective, however, need to be supported by strong legislation and leadership. Only four of the five countries involved in this multi-site study have ratified the Framework Convention on Tobacco Control, and even where it has been ratified, implementation is uneven.Supplement: 1</p
A power-splitting relaying protocol for wireless energy harvesting and information processing in NOMA systems
Non-orthogonal multiple access (NOMA) along with cooperative communications have been recognized as promising candidates for the fifth generation (5G) wireless networks and have attracted many researchers. Every networked device however has its own limited power supply. To this extent, this paper investigates a power-splitting relaying (PSR) protocol for wireless energy harvesting and information processing in the NOMA systems to prolong the lifetime of the energy-constrained relay nodes in wireless networks so as to avail the ambient radio-frequency (RF) signal as well as to simultaneously harvest the energy and process the information. Decode-and-forward relaying is employed at the relay node where the energy from the received RF signal is harvested and exploited to forward the information to the destination. Specifically, the outage probability and ergodic rate of the PSR protocol are derived to realize the impacts of energy harvesting time, energy harvesting efficiency, power splitting ratio, source data rate, and the distance between nodes. It is also shown that an increased energy harvesting efficiency results in an enhanced performance and an outperformance in terms of the energy efficiency is achieved with the employment of the NOMA when compared to the conventional orthogonal multiple access. Numerical results are provided to verify the findings
Modelling the progression of pandemic influenza A (H1N1) in Vietnam and the opportunities for reassortment with other influenza viruses
BACKGROUND: A novel variant of influenza A (H1N1) is causing a pandemic and, although the illness is usually mild, there are concerns that its virulence could change through reassortment with other influenza viruses. This is of greater concern in parts of Southeast Asia, where the population density is high, influenza is less seasonal, human-animal contact is common and avian influenza is still endemic. METHODS: We developed an age- and spatially-structured mathematical model in order to estimate the potential impact of pandemic H1N1 in Vietnam and the opportunities for reassortment with animal influenza viruses. The model tracks human infection among domestic animal owners and non-owners and also estimates the numbers of animals may be exposed to infected humans. RESULTS: In the absence of effective interventions, the model predicts that the introduction of pandemic H1N1 will result in an epidemic that spreads to half of Vietnam's provinces within 57 days (interquartile range (IQR): 45-86.5) and peaks 81 days after introduction (IQR: 62.5-121 days). For the current published range of the 2009 H1N1 influenza's basic reproductive number (1.2-3.1), we estimate a median of 410,000 cases among swine owners (IQR: 220,000-670,000) with 460,000 exposed swine (IQR: 260,000-740,000), 350,000 cases among chicken owners (IQR: 170,000-630,000) with 3.7 million exposed chickens (IQR: 1.9 M-6.4 M), and 51,000 cases among duck owners (IQR: 24,000 - 96,000), with 1.2 million exposed ducks (IQR: 0.6 M-2.1 M). The median number of overall human infections in Vietnam for this range of the basic reproductive number is 6.4 million (IQR: 4.4 M-8.0 M). CONCLUSION: It is likely that, in the absence of effective interventions, the introduction of a novel H1N1 into a densely populated country such as Vietnam will result in a widespread epidemic. A large epidemic in a country with intense human-animal interaction and continued co-circulation of other seasonal and avian viruses would provide substantial opportunities for H1N1 to acquire new genes
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