Models of collective cell motion for cell populations with different aspect ratio : diffusion, proliferation and travelling waves

Continuum, partial differential equation models are often used to describe the collective motion of cell populations, with various types of motility represented by the choice of diffusion coefficient, and cell proliferation captured by the source terms. Previously, the choice of diffusion coefficient has been largely arbitrary, with the decision to choose a particular linear or nonlinear form generally based on calibration arguments rather than making any physical connection with the underlying individual-level properties of the cell motility mechanism. In this work we provide a new link between individual-level models, which account for important cell properties such as varying cell shape and volume exclusion, and population-level partial differential equation models. We work in an exclusion process framework, considering aligned, elongated cells that may occupy more than one lattice site, in order to represent populations of agents with different sizes. Three different idealizations of the individual-level mechanism are proposed, and these are connected to three different partial differential equations, each with a different diffusion coefficient; one linear, one nonlinear and degenerate and one nonlinear and nondegenerate. We test the ability of these three models to predict the population level response of a cell spreading problem for both proliferative and nonproliferative cases. We also explore the potential of our models to predict long time travelling wave invasion rates and extend our results to two dimensional spreading and invasion. Our results show that each model can accurately predict density data for nonproliferative systems, but that only one does so for proliferative systems. Hence great care must be taken to predict density data for with varying cell shape.

Estimation on disease burden related to hepatitis B virus infection in Shandong province of China [山东省乙型肝炎病毒感染所致相关疾病的疾病负担研究]

Objective: To comprehensively measure the burden of hepatitis B, liver cirrhosis and liver cancer in Shandong province, using disability-adjusted life years (DALYs) to estimate the disease burden attribute to hepatitis B virus (HBV)infection. Methods: Based on the mortality data of hepatitis B, liver cirrhosis and liver cancer derived from the third National Sampling Retrospective Survey for Causes of Death during 2004 and 2005, the incidence data of hepatitis B and the prevalence and the disability weights of liver cancer gained from the Shandong Cancer Prevalence Sampling Survey in 2007, we calculated the years of life lost (YLLs), years lived with disability (YLDs) and DALYs of three diseases following the procedures developed for the global burden of disease (GBD) study to ensure the comparability. Results: The total burden for hepatitis B, liver cirrhosis and liver cancer were 211 616 (39 377 YLLs and 172 239 YLDs), 16 783 (13 497 YLLs and 3286 YLDs) and 247 795 (240 236 YLLs and 7559 YLDs) DALYs in 2005 respectively, and men were 2.19, 2.36 and 3.16 times as that for women, respectively in Shandong province. The burden for hepatitis B was mainly because of disability (81.39%). However, most burden on liver cirrhosis and liver cancer were due to premature death (80.42% and 96.95%). The burden of each patient related to hepatitis B, liver cirrhosis and liver cancer were 4.8, 13.73 and 11.11 respectively. Conclusion: Hepatitis B, liver cirrhosis and liver cancer caused considerable burden to the people living in Shandong province, indicating that the control of hepatitis B virus infection would bring huge potential benefits.

Estimation on the mortality and disease burden attributed to selected risk factors in Shandong province [山东省主要危险因素的归因死亡和疾病负担分析]

Objective: To determine the major health related risk factors and provide evidence for policy-making,using health burden analysis on selected factors among general population from Shandong province. Methods: Based on data derived from the Third Death of Cause Sampling Survey in Shandong. Years of life lcrat(YLLs),yearS Iived with disability(YLDs)and disability-adjusted life years(DALYs) were calculated according to the GBD ethodology.Deaths and DALYs attributed to the selected risk factors were than estimated together with the PAF data from GBD 2001 study.The indirect method was employed to estimate the YLDs. Results: 51.09%of the total dearlls and 31.83%of the total DALYs from the Shandong population were resulted from the 19 selected risk factors.High blood pre.ure,smoking,low fruit and vegetable intake,aleohol consumption,indoor smoke from solid fuels,high cholesterol,urban air pollution, physical inactivity,overweight and obesity and unsafe injections in health care settings were identified as the top 10 risk faetors for mortality which together caused 50.21%of the total deaths.Alcohol use,smoking,high blood pressure,Low fruit and vegetable intake, indoor smoke from solid fuels, overweight and obesity,high cholesterol, physical inactivity,urban air pollution and iron-deficiency anemia were proved as the top 10 risk factors related to disease burden and were responsible for 29.04%of the total DALYs. Conclusion: Alcohol use.smoking and high blood pressure were determined as the major risk factors which influencing the health of residents in Shandong. The mortality and burden of disease could be reduced significantly if these major factors were effectively under control.

An aspect query language model based on query decomposition and high-order contextual term associations

In information retrieval (IR) research, more and more focus has been placed on optimizing a query language model by detecting and estimating the dependencies between the query and the observed terms occurring in the selected relevance feedback documents. In this paper, we propose a novel Aspect Language Modeling framework featuring term association acquisition, document segmentation, query decomposition, and an Aspect Model (AM) for parameter optimization. Through the proposed framework, we advance the theory and practice of applying high-order and context-sensitive term relationships to IR. We first decompose a query into subsets of query terms. Then we segment the relevance feedback documents into chunks using multiple sliding windows. Finally we discover the higher order term associations, that is, the terms in these chunks with high degree of association to the subsets of the query. In this process, we adopt an approach by combining the AM with the Association Rule (AR) mining. In our approach, the AM not only considers the subsets of a query as “hidden” states and estimates their prior distributions, but also evaluates the dependencies between the subsets of a query and the observed terms extracted from the chunks of feedback documents. The AR provides a reasonable initial estimation of the high-order term associations by discovering the associated rules from the document chunks. Experimental results on various TREC collections verify the effectiveness of our approach, which significantly outperforms a baseline language model and two state-of-the-art query language models namely the Relevance Model and the Information Flow model

A 2-h diagnostic protocol to assess patients with chest pain symptoms in the Asia-Pacific region (ASPECT): a prospective observational validation study

Background: Patients with chest pain contribute substantially to emergency department attendances, lengthy hospital stay, and inpatient admissions. A reliable, reproducible, and fast process to identify patients presenting with chest pain who have a low short-term risk of a major adverse cardiac event is needed to facilitate early discharge. We aimed to prospectively validate the safety of a predefined 2-h accelerated diagnostic protocol (ADP) to assess patients presenting to the emergency department with chest pain symptoms suggestive of acute coronary syndrome. Methods: This observational study was undertaken in 14 emergency departments in nine countries in the Asia-Pacific region, in patients aged 18 years and older with at least 5 min of chest pain. The ADP included use of a structured pre-test probability scoring method (Thrombolysis in Myocardial Infarction [TIMI] score), electrocardiograph, and point-of-care biomarker panel of troponin, creatine kinase MB, and myoglobin. The primary endpoint was major adverse cardiac events within 30 days after initial presentation (including initial hospital attendance). This trial is registered with the Australia-New Zealand Clinical Trials Registry, number ACTRN12609000283279. Findings: 3582 consecutive patients were recruited and completed 30-day follow-up. 421 (11•8%) patients had a major adverse cardiac event. The ADP classified 352 (9•8%) patients as low risk and potentially suitable for early discharge. A major adverse cardiac event occurred in three (0•9%) of these patients, giving the ADP a sensitivity of 99•3% (95% CI 97•9–99•8), a negative predictive value of 99•1% (97•3–99•8), and a specificity of 11•0% (10•0–12•2). Interpretation: This novel ADP identifies patients at very low risk of a short-term major adverse cardiac event who might be suitable for early discharge. Such an approach could be used to decrease the overall observation periods and admissions for chest pain. The components needed for the implementation of this strategy are widely available. The ADP has the potential to affect health-service delivery worldwide.

Principals’ and teacher leaders’ perceptions of their role and interaction under current Chinese reform : a case study in Shandong province

This study aims to explore the perceptions of principals and teacher leaders regarding their roles and the interaction between these roles in Chinese urban primary schools at the time of unprecedented curriculum reform. This involves a complexity of factors such as the influence of globalisation, the impact of traditional Chinese cultural attitudes towards education through Confucianism, and the implementation requirements of the current education reforms. All of these wider contextual factors help to shape the leadership practices that are described in the study. A qualitative exploratory case study approach has been utilised to undertake this investigation. The conceptual framework for this study draws upon scholars‘ work from Western countries but has been adapted in order to address three research questions for the study‘s focus on the context in Shandong province, Mainland China. Three research questions were addressed: First, what are principals‘ perceptions of their leadership roles in Mainland China under current educational reform? Second, what are teacher leaders‘ perceptions of their leadership roles in Mainland China under current educational reform? And finally, what are principals‘ and teacher leaders‘ perceptions of how their roles interact? With reference to the principals in the study, the findings confirm Gurr‘s (2008) comprehensive leadership model relating to four roles, specifically, learning and teaching, symbolic and cultural awareness, future orientation, and accountability. Significantly, some sub-roles that emerge from the data are uniquely Chinese. For example, school culture construction is a very deliberate process in which principals and their staff talked openly about and were involved in creating a positive school climate comprising spiritual, material, and system dimensions. Another finding relates to school feature construction. This refers to the process that principals and staff used to make their schools distinctive and different from other schools and included such features as the school‘s philosophy and the school-based curriculum. In seeking to understand the nature of teacher leadership in Chinese primary schools, this research confirms some findings identified in Western literature. For instance, teacher leaders in Shandong province were involved in decision-making, working with parents and community members, undertaking and planning professional development for staff, and mediating between colleagues (Day & Harris, 2002; Harrison & Killion, 2007; Leithwood, Jantzi, & Steinbach, 1999; Muijs & Harris, 2006; Smylie, 1992). However, some new aspects, such as a heightened awareness of the importance of accountability, emerge from this study. The study‘s conceptual framework also draws upon some significant insights from micropolitics and, in particular, two core constructs, namely cooperation and conflict (Blase, 1991), to explore the interactions between principals and teacher leaders. In this study, principals and teacher leaders employed exchange and facilitation as two strategies in cooperative processes; and they adopted enforcement and compromise in conflictive processes. Finally, the study‘s findings indicate that principals and teacher leaders were developing new ways of interacting in response to the requirements of significant education reform. Most principals were exercising their power through (Blase, 1991) their teacher leaders who in turn, were working in alignment with their principals to achieve the desired outcomes in schools. It was significant that this form of 'parallel leadership' (Crowther, Ferguson, & Ham, 2009) characterised the teacher leadership roles at this period of change to the curriculum in Mainland China.

Biodiversity–productivity relationships in small-scale mixed-species plantations using native species in Leyte province, Philippines

In this study, we investigate the relationship between tree species diversity and production in 18 mixed-species plantations established under the Rainforestation Farming system in Leyte province, the Philippines. The aim was to quantify productivity in the mixed-species plantations in comparison to the monocultures, and identify key drivers of productivity including environmental conditions, stand structural characteristics and surrogate measures of biodiversity, i.e. species richness, Shannon’s diversity index and functional groups. We found that monocultures had a much higher productivity than mixtures of the same and other species. In the mixtures, biodiversity and productivity did not have a simple relationship. Instead the proportion of exotic and native species, and the proportion of fast-growing species had a marginally significant positive effect on stand productivity, but no significant relationship was found with species richness or Shannon’s diversity. Instead stand structural characteristics such as density and age were the strongest drivers of increased productivity. Production levels within the mixed-species plantations varied significantly between sites. Overall, we found that the productivity of mixed species plantations was driven more by the characteristics of species present and stand structural characteristics then by simply the number and abundance of species, which suggests management practices are key for balancing multiple objectives to meet sustainable development needs.

Aspect oriented business process modeling with precedence

Complexity is a major concern which is aimed to be overcome by people through modeling. One way of reducing complexity is separation of concerns, e.g. separation of business process from applications. One sort of concerns are cross-cutting concerns i.e. concerns which are scattered and tangled through one of several models. In business process management, examples of such concerns are security and privacy policies. To deal with these cross-cutting concerns, the aspect orientated approach was introduced in the software development area and recently also in the business process management area. The work presented in this paper elaborates on aspect oriented process modelling. It extends earlier work by defining a mechanism for capturing multiple concerns and specifying a precedence order according to which they should be handled in a process. A formal syntax of the notation is presented precisely capturing the extended concepts and mechanisms. Finally, the relevant of the approach is demonstrated through a case study.

How do supercontinents break up? — assessing the continental large igneous province (LIP) record of the break-up of Pangea

LIP emplacement is linked to the timing and evolution of supercontinental break-up. LIP-related break-up produces volcanic rifted margins, new and large (up to 108 km2) ocean basins, and new, smaller continents that undergo dispersal and potentially reassembly (e.g., India). However, not all continental LIPs lead to continental rupture. We analysed the <330 Ma continental LIP record(following final assembly of Pangea) to find relationships between LIP event attributes (e.g., igneous volume, extent, distance from pre-existing continental margin) and ocean basin attributes (e.g., length of new ocean basin/rifted margin) and how these varied during the progressive break up of Pangea. No correlation exists between LIP magnitude and size of the subsequent ocean basin or rifted margin. Our review suggests a three-phased break-up history of Pangea: 1) “Preconditioning” phase (∼330–200 Ma): LIP events (n=7) occurred largely around the supercontinental margin clustering today in Asia, with a low (<20%) rifting success rate. The Panjal Traps at ∼280 Ma may represent the first continental rupturing event of Pangea, resulting in continental ribboning along the Tethyan margin; 2) “Main Break-up” phase (∼200–100 Ma): numerous large LIP events(n=10) in the supercontinent interior, resulting in highly successful fragmentation (90%) and large, new ocean basins(e.g., Central/South Atlantic, Indian, >3000 km long); 3) “Waning” phase (∼100–0 Ma): Declining LIP magnitudes (n=6), greater proximity to continental margins (e.g., Madagascar, North Atlantic, Afro-Arabia, Sierra Madre) producing smaller ocean basins (<2600 km long). How Pangea broke up may thus have implications for earlier supercontinent reconstructions and LIP record.

Cause of Death, Trend and Disease Burden in Shandong Province, China : the Third Retrospective Sampling Survey of Cause of Death Report

This book describes the mortality for all causes of death and the trend in major causes of death since 1970s in Shandong Province, China.

Impact of socio-ecological variability on the transmission of malaria in Yunnan Province, China

This thesis is a population-based epidemiological study to explore the spatial and temporal pattern of malaria, and to assess the relationship between socio-ecological factors and malaria in Yunnan, China. Geospatial and temporal approaches were applied; the high risk areas of the disease were identified; and socio-ecological drivers of malaria were assessed. These findings will provide important evidence for the control and prevention of malaria in China and other countries with a similar situation of endemic malaria.

Alcohol-related driving offences, crashes, and traffic policing strategies in Zhejiang Province, China

Context Alcohol-related traffic offences and associated trauma have attracted attention in China in recent years, culminating in changes to national legislation in May 2011. Harsher penalties were introduced, particularly for offences where blood alcohol concentration (BAC) levels above 80mg/100mL are recorded. Deemed to be drunk under the law, this is now a criminal offence attracting penalties including large monetary fines, licence suspension for 5 years and imprisonment. Objective This paper outlines key statistics about alcohol-related road trauma in Zhejiang Province and strategies used to combat drink- and drunk-driving. Key Outcomes Zhejiang Province, in China’s south east, has a population of approximately 54, 426,000; 22.36% hold a driving licence. Rapid motorisation is occurring there. In 2011, 1,383,318 new licences were issued, representing a 16.78% increase from the previous year. In 2012, there were a total of 65,000 police officers throughout the Province, 12,307 of whom (18.9%) were traffic police. Responsibility for conducting alcohol testing is the responsibility of all traffic police. The number of alcohol breath tests conducted per year was not available. However, traffic police are actively enforcing alcohol-related laws. In 2011, 89,228 drivers were charged with drink-driving (DUI;20-80mg/100 mL) and 10,014 with the more serious drunk-driving offence (DWI;>80mg/100mL) (Zhejiang Traffic Management Department, 2012). These numbers decreased from the previous year (221,262 and 26,390 respectively). For all crashes recorded in 2011 (n=20,176), 2% involved alcohol-impaired road users. Information on the role of alcohol in crashes from previous years was not available. Discussion Various strategies are employed to detect alcohol-impaired drivers including: targeting vehicles from hotels/restaurants; using sense of smell to screen drivers for further testing; passive alcohol sensors to test drivers; and blood tests for crash-involved drivers where a fatality occurred. Although resources to promote road safety are limited, various government initiatives promote awareness of the dangers of alcohol-related driving and more are needed in future.

Hybrid antibacterial fabrics with extremely high aspect ratio Ag/AgTCNQ nanowires

This study reports the synthesis of extremely high aspect ratios (>3000) organic semiconductor nanowires of Ag–tetracyanoquinodimethane (AgTCNQ) on the surface of a flexible Ag fabric for the first time. These one-dimensional (1D) hybrid Ag/AgTCNQ nanostructures are attained by a facile, solution-based spontaneous reaction involving immersion of Ag fabrics in an acetonitrile solution of TCNQ. Further, it is discovered that these AgTCNQ nanowires show outstanding antibacterial performance against both Gram negative and Gram positive bacteria, which outperforms that of pristine Ag. The outcomes of this study also reflect upon a fundamentally important aspect that the antimicrobial performance of Ag-based nanomaterials may not necessarily be solely due to the amount of Ag+ ions leached from these nanomaterials, but that the nanomaterial itself may also play a direct role in the antimicrobial action. Notably, the applications of metal-organic semiconducting charge transfer complexes of metal-7,7,8,8-tetracyanoquinodimethane (TCNQ) have been predominantly restricted to electronic applications, except from our recent reports on their (photo)catalytic potential and the current case on antimicrobial prospects. This report on growth of these metal-TCNQ complexes on a fabric not only widens the window of these interesting materials for new biological applications, it also opens the possibilities for developing large-area flexible electronic devices by growing a range of metal-organic semiconducting materials directly on a fabric surface.

Measuring the burden of disease in Shandong province : an adoption of the disability-adjusted life year [应用伤残调整寿命年测量山东省居民疾病负担]

Objective To estimate the burden of diseases in Shandong province by the means of DALY (Disability- adjusted life year) thus to investigate the key public health problems referencing for health policy making. Methods DALYs were calculated following the procedures developed for the Global Burden of Disease (GBD) study to ensure comparability. We measured YLLs using the mortality data of 19 Disease Surveillance Points (DSPs) in Shandong Province during 2000 and 2005. YLDs were estimated based on data for WPRO in the 2002 GBD study published by WHO. Results During this period, the average DALYs loss by all causes for the residents of DSPs in Shandong was 149.74 per thousand persons each year. Noncommunicable diseases accounted for 76.63% of the disability adjusted life years, communicable diseases and other disorders represented 14.13%, and injuries 9.24%. Nearly half of the DALYs (45%) happened among the elderly (60+). Malignant neoplasm was the number one cause of DALYs loss in the male, followed by neuropsychiatric disorder, injury, cerebrovascular disease, heart disease，etc. However, neuropsychiatric disorder possessed the largest single contributor to DALY in the female and followed by heart disease, malignant neoplasm, cerebrovascular disease and respiratory disease. Conclusion Non-communicable diseases such as circulatory diseases, neuropsychiatric disorders and malignant neoplasms were the main causes of disease burden in Shandong province. The importance of neuropsychiatric disorders was more striking and should be recognized properly. The lack of morbidity data is the main limitation of this study. Abstract in Chinese 目的 应用伤残调整寿命年测量山东省居民疾病负担,提出该地区主要卫生问题,为卫生决策提供科学依据. 方法 以山东省2000-2005年19个疾病监测点的死因监测资料为基础,利用世界卫生组织(WHO)提供的方法计算不同疾病在不同性别年龄人群所造成的伤残调整寿命年(DALYs),其中,YIJDs根据WHO公布的亚太区2002年疾病负担数据进行估算. 结果 2000-2005年山东省疾病监测系统居民因为早死和残疾年平均损失149.74个DALYs/千人,其中,76.6%的DALYs损失因慢性非传染性疾病所致,14.1%由传染性疾病等引起,9.2%因为意外伤害造成;接近1/2(45%)的DALYs损失发生在60岁以上人群;恶性肿瘤为造成男性居民DALYs损失的首位原因,其次为精神行为疾患、意外伤害、脑血管病和心脏病等,女性居民则以精神行为疾患为DALYs首位原因,其次为心脏病、恶性肿瘤、脑血管病和呼吸系统疾病. 结论 以循环系统疾病、精神行为疾惠和恶性肿瘤为首的慢性非传染性疾病为造成山东省疾病负担DALYs损失的主要原因.对于精神行为疾患的重要性的认识有待于进一步提高,研究的主要局限性在于发病率资料的缺乏.