Trees under attack: a Ray-Knight representation of Feller's branching diffusion with logistic growth

We obtain a representation of Feller's branching diffusion with logistic growth in terms of the local times of a reflected Brownian motion $H$ with a drift that is affine linear in the local time accumulated by $H$ at its current level. As in the classical Ray-Knight representation, the excursions of $H$ are the exploration paths of the trees of descendants of the ancestors at time $t=0$, and the local time of $H$ at height $t$ measures the population size at time $t$ (see e.g. \cite{LG4}). We cope with the dependence in the reproduction by introducing a pecking order of individuals: an individual explored at time $s$ and living at time $t=H_s$ is prone to be killed by any of its contemporaneans that have been explored so far. The proof of our main result relies on approximating $H$ with a sequence of Harris paths $H^N$ which figure in a Ray-Knight representation of the total mass of a branching particle system. We obtain a suitable joint convergence of $H^N$ together with its local times {\em and} with the Girsanov densities that introduce the dependence in the reproduction

The progressivity and regressivity of aid to the social sectors

This paper analyses the distribution of total aid and aid to the social sectors between 2009 and 2011. Its key findings are four-fold. First, despite the stated objectives of donors, total aid disbursements are broadly neutral, favouring neither the most deprived nor relatively well-off countries. Second, the pattern of social sector aid disbursements follows those for total aid. Third, the aid allocation patterns of bilateral and multilateral donors differ, with multilateral donors generally being more focused on the poorest countries. Finally, the distribution of aid for health and population is more progressive than that for education or other social sectors

The case for hybrid ventilated primary schools in Ho Chi Minh City in Vietnam

This study investigates indoor environmental quality and users’ perception in 14 classrooms of a mixed-mode ventilated primary school in Ho Chi Minh City, Vietnam, during the rainy season by qualitative and quantitative research methods. Spot and long-term measurements were recorded, covering a range of environmental parameters such as air temperature, relative humidity, CO2 concentration level, illuminance and sound level. A questionnaire was conducted and answered by 451 children (eight to eleven year olds) to investigate their perception of the thermal and visual comfort, indoor air quality, noise and overall comfort in the classrooms. In addition, 14 teachers were asked to inform the study about their experiences and behaviours in the classrooms. The results were analysed by cross relating the measured environmental conditions and the comfort vote on a seven-point scale

An analysis of thermal comfort in primary schools in Vietnam

There is a trend of installing air conditioning systems in public primary schools that are currently naturally ventilated in Vietnam. A previous study conducted by the authors provided evidence that there is limited need for air conditioning in Vietnamese mid-season and the hottest season. In this study, the authors investigated thermal comfort and users’ perceptions in three primary schools in Ho Chi Minh City during the hottest season (April 2016) and the coldest season (December 2016 – January 2017). In-situ spot and long-term measurements were recorded. Questionnaires were completed by 3,960 children (age range from 8 to 11 years) and the teachers to inform the study about their experiences and the extent of their interaction with the building in 97 free-running classrooms. The results were analysed by correlating the conditions measured and the comfort mean votes. The neutral temperatures were respectively 31.7oC and 31.1oC for the hottest and coldest seasons. Children were observed to tolerate higher thermal comfort condition than the recommended values in the standards. Compared with the results of the hottest season, the thermal sensation mean vote reduced from (0.29) to (0.12) when the decrease of the mean temperature was from 33.3oC to 31.8oC in the coldest season. The temperature of 33oC was proposed for the overheating benchmark. The results indicated that Vietnamese children adapted to hot climate and had higher thermal comfort tolerance than adults. Preliminary findings suggest that it is unnecessary to use air conditioning system all year round. These findings could help and encourage architects and engineers to deliver schools reaching acceptable comfort levels without the need of air conditioning system

Children thermal comfort in primary schools in Ho Chi Minh City in Vietnam

Indoor environmental quality significantly impacts on students’ performance and productivity, particularly thermal comfort levels. Currently in Vietnam, very few studies have dealt with the issue and the current trend is to install energy-intensive air-conditioning in primary schools as this is perceived as more comfortable. In this study, the authors investigated the users’ perceptions of thermal comfort in three primary schools in Ho Chi Minh City during the mid-season (September 2015) and the hottest season (April 2016). In-situ spot and long-term measurements were recorded. Questionnaires were completed by 2,145 children (from 8 to 11 years-old) and 62 teachers to understand their experiences and the extent of their interaction with the building in 62 naturally ventilated classrooms. The results were analysed by correlating the conditions measured and the comfort mean votes. Throughout this study, children were observed to tolerate higher thermal comfort condition than the recommended values in the standards. Around 7% of the occupied time during academic year presented temperatures over 33oC, in which less than 80% of the children voted acceptable. The results indicated that Vietnamese children had higher thermal comfort tolerance than the comfort levels suggested in the standards. Using air conditioning system all year round was deemed unnecessary

The Need for School-Based Teen Dating Violence Prevention

Schools have several competing demands, and often suffer from inefficient access to needed resources. Thus, the addition of any program into an already overtaxed school system must be met with convincing evidence that 1) a need or problem exists and is relevant to the education of students, 2) the problem is amenable to change, and 3) addressing the problem is in the best interest of educators and students. The purpose of the present paper is to present a case for inclusion of teen dating violence prevention programs in middle and high schools. We also discuss a recent survey of 219 employees of a suburban school district in southeast Texas. Specifically, we examined their perceived need for and appropriateness of a school-based dating violence prevention program. The anonymous internet-based survey revealed that a majority of participants believed that teen dating violence was a problem, 19% reported having observed an instance of teen dating violence, and 82% believed school to be an appropriate outlet for the implementation of a dating violence prevention program

Examining the effects of lead on the life of larval zebrafish (1-7 days old)

Lead (Pb) is a toxic metal and and can cause variety of disorders and effect on neu-ronal function and neurodevelopment. Using zebrafish as a model, the aim of this study was to evaluate the effects of concentrations of Pb2+ on the life of zebrafish larvae (from 1 to 7 days old)yesBelgorod State Universit

The effect of trust on knowledge sharing between project teams

Although there has been many studies that were conducted over the years about trust and its influence on knowledge sharing, the phenomenon in the context of project teams still remains ambiguous in theory and in practice. Moreover, managers often have difficulty in creating a workspace that team members are able to generate trust in order to encourage knowledge sharing. For this reason, this current research aims to examine three forms of trust namely: affect-based trust, cognition-based trust, and information-based trust, and their influences on the sharing of knowledge of project teams. In order to successfully conduct the research, the researcher shall provide an empirical investigation to explain the proposed relationships between the three forms of trust and knowledge sharing regarding project team members in various organizations by implementing a quantitative methodology research. A survey data of 256 responses was used to conduct confirmatory factor analysis and hierarchical multiple regression, and the hypotheses were tested. The results indicate that all the three proposed relationships between trust and knowledge sharing are positively and significantly supported, with affect-based trust being the most significant influence on knowledge sharing. Consequently, this research provides insights for managers about the value of project team members’ trust on their sharing of knowledge and proposes future directions for improvement

Analytical characteristics and comparative evaluation of Aptima HCV quant Dx assay with the Abbott RealTime HCV assay and Roche COBAS AmpliPrep/COBAS TaqMan HCV quantitative test v2.0

Abstract Background The Aptima HCV Quant Dx assay (Aptima assay) is a fully automated quantitative assay on the Panther® system. This assay is intended for confirmation of diagnosis and monitoring of HCV RNA in plasma and serum specimens. The purpose of the testing described in this paper was to evaluate the performance of the Aptima assay. Methods The analytical sensitivity, analytical specificity, precision, and linearity of the Aptima assay were assessed. The performance of the Aptima assay was compared to two commercially available HCV assays; the Abbott RealTime HCV assay (Abbott assay, Abbott Labs Illinois, USA) and the Roche COBAS Ampliprep/COBAS Taqman HCV Quantitative Test v2.0 (Roche Assay, Roche Molecular Systems, Pleasanton CA, USA). The 95% Lower Limit of Detection (LoD) of the assay was determined from dilutions of the 2nd HCV WHO International Standard (NIBSC 96/798 genotype 1) and HCV positive clinical specimens in HCV negative human plasma and serum. Probit analysis was performed to generate the 95% predicted detection limits. The Lower Limit of Quantitation (LLoQ) was established for each genotype by diluting clinical specimens and the 2nd HCV WHO International Standard (NIBSC 96/798 genotype 1) in HCV negative human plasma and serum. Specificity was determined using 200 fresh and 536 frozen HCV RNA negative clinical specimens including 370 plasma specimens and 366 serum specimens. Linearity for genotypes 1 to 6 was established by diluting armored RNA or HCV positive clinical specimens in HCV negative serum or plasma from 8.08 log IU/mL to below 1 log IU/mL. Precision was tested using a 10 member panel made by diluting HCV positive clinical specimens or spiking armored RNA into HCV negative plasma and serum. A method comparison was conducted against the Abbott assay using 1058 clinical specimens and against the Roche assay using 608 clinical specimens from HCV infected patients. In addition, agreement between the Roche assay and the Aptima assay using specimens with low HCV concentrations (</= 25 IU/mL by Roche) was tested using 107 clinical specimens. Results The 95% LoD was 5.1 IU/mL or lower for serum and 4.8 IU/mL or lower for plasma depending on the HCV genotype. The LLoQ for the assay was 10 IU/mL. Specificity was 100% with 95% confidence intervals of 99.6 to 100% for serum and plasma data combined. The assay demonstrated good linearity across the range for all genotypes. The Precision as estimated by the standard deviation (sd) was 0.17 log or lower across the range of the assay for both serum and plasma. HCV viral load results were compared using the Aptima assay and the Abbott assay giving a slope of 1.06, an intercept of 0.08 and an R2 of 0.98. HCV viral load results were compared for the Aptima and Roche assays giving a slope of 1.05, an intercept of −0.12 and an R2 of 0.96. Positive and negative agreement for the Aptima assay vs the Roche assay was 89% for low level specimens. Conclusion The Aptima assay is a highly sensitive and specific assay. The assay gave comparable HCV viral load results when compared to the Abbott and Roche assays. The performance of the Aptima assay makes it an excellent candidate for the detection and monitoring of HCV