The 8 July 2002 storm over Athens: analysis of the Kifissos River/Canal overflows

We analyse the flood event of 8 July 2002 that caused overflows over portions of the lower reach of the Kifissos River/Canal. The storm covered only the lower basin area and was concentrated on the centre and the southwest side of Greater Athens. The issue that stirred the public opinion was whether the hydraulic works underway in lower Kifissos at that time were responsible for the overflows. We explore this issue with the hydrologic-hydraulic model of the Kifissos basin TELESIM. To shed light on the probable cause of the observed flooding, we ran TELESIM for two rain-field scenarios derived from the recorded point-rainfalls, computing flows for each scenario. Depth profiles for channel conditions without obstructions do not explain the observed flooding. With the channel taken as locally obstructed by flow-area reducing ramps plus bed-debris, estimated nominal overflows (bank-full level is threshold, but the water stays inside the channel) compare well with actual ones for the milder rainfall scenario. Hence, the simulations support as plausible the hypothesis that flow obstructions due to the construction caused the overflows

Analisi degli effetti dell'eterogeneità cellulare di un tessuto del nodo seno-atriale simulato attraverso la parallelizzazione in CUDA

Il nodo seno-atriale (NSA) è un piccolo tessuto responsabile della frequenza cardiaca in condizioni fisiologiche. Sua principale caratteristica è l’autoritmicità: non necessita di stimoli esterni per generale un potenziale d’azione. Il tessuto NSA è composto da cellule con morfologia differente che generano potenziali d’azione leggermente diversi. Quando più cellule sono collegate elettricamente danno luogo a fenomeni non osservabili in single cell (comportamento emergente). I modelli computazionali sono uno strumento utile per indagare fenomeni difficilmente osservabili in vitro, sia a livello di singola cellula che su scala tissutale. L’obiettivo di questa tesi è duplice: (i) individuare il miglior ambiente computazionale per simulare tessuti di NSA e (ii) osservare gli effetti dell’eterogeneità e dell’accoppiamento cellulare a livello tissutale utilizzando il modello SeveriDiFrancesco, che descrive il potenziale d’azione di una cellula di NSA di coniglio. La scelta dell’ambiente di simulazione ha messo a confronto il costo computazionale di metodi a passo fisso e a passo variabile in Matlab, C++ e CUDA. Sono stati simulati tessuti composti da 100 cellule per 2 secondi. I metodi C++ e CUDA sono stati confrontati per 100, 400, 900, 1600 cellule, mettendo in risalto come CUDA sia l’ambiente più adatto su cui lanciare le simulazioni. Per valutare gli effetti dell’eterogeneità sono stati simulati tessuti di 400 cellule per 20 secondi, accoppiate tra loro con rho = 1, 10, 100 1000 e 10000 MΩ m. L’eterogeneità è stata implementata randomizzando i valori delle conducibilità di membrana attraverso una distribuzione lognormale con σ = 0.05, 0.1, 0.1873, 0.3, 0.4. Le cellule accoppiate si sincronizzano su frequenze inferiori alle frequenze medie della popolazione cellulare e del modello di cellula isolata con valori nominali. Inoltre la frequenza diminuisce al diminuire dell’accoppiamento. Il biomarker APA diminuisce al diminuire dell’accoppiamento

Learning tennis skill through game Play and Stay in elementary pupils

This study aimed to examine the effect of Play and Stay tennis program on learning the service skill on Elementary School pupils and the development of their satisfaction. Sixty-two (62) 5th class Elementary pupils, aged 11 years (Mean Age=11.13, SD=0.33) took part. The pupils, from four classes of two national elementary schools (two classes from each school), were divided into two groups: the experimental group which followed the Play and Stay program, and the control group which followed the traditional teaching method. The four-week course was held during the Physical Education lessons, (20 min of 3 hours/week). A quantitative evaluation was made on 10 trials at the service by each pupil. The qualitative evaluation of the technique was made (video-taping, observation, and a 5-element skill assessment) for service learning, comprising of: an initial test at the beginning, a final test at the end, and a retention test one week after completing the program without any practice. At the end of the course, all participants completed a feedback questionnaire on the level of satisfaction with the program. ANOVA repeated measures revealed significant interaction between groups and measurements for technique evaluation (F(2.120)=30.82, p<0.01), as well as the outcome of service skill (F(2.120)=10.44, p<0.01). The t-test analysis for independent samples showed significant differences between the experimental and the control group in four of the six variables on the satisfaction questionnaire. These findings indicate that the Play and Stay tennis teaching program was effective in helping pupils to learn the service skill, while simultaneously having fun and enjoying the procedure. This suggests that students will be motivated to become more involved in tennis as a sport, since enjoyment and satisfaction stimulate interest in participation

Mathematical predictive models for cooling ponds and lakes. Part B, User's manual and applications of MITEMP. Part C. A transient analytical model for shallow cooling ponds

"Also published as R.M. Parsons Laboratory Technical Report No. 262."In Part B a computer code, '"MITEMP: M.I.T. Transient Temperature Prediction Model for Natural Reservoirs and Cooling Impoundments," is presented as a feasible and efficient tool for the prediction of transient performance of man-made impoundments. Particular emphasis is placed on waste heat dissipation from steam-electric power stations. The code allows the simulation of the physical regime (temperature and flow patterns) of impoundments as a function of design and for long time periods. The code contains the following elements: (1) Natural Deep Lake and Reservoir Model, (2) Deep Stratified Cooling Pond Model, (3) Shallow Vertically Mixed Dispersive Cooling Pond Model, and (4) Shallow, Vertically Mixed Recirculating Cooling Pond Model. The physical and mathematical basis for the present computer code is developed in an earlier report entitled, "Mathematical Predictive Models for Cooling Ponds and Lakes, Part A: Model Development and Design Considerations," by G. Jirka, M. Watanabe, K.H. Octavio, C. Cerco and D.R.F. Harleman, R.M. Parsons Laboratory for Water Resources and Hydrodynamics, Technical Report No. 238, December 1978. The user's manual presented herein gives a detailed description of the computational structure of MITEMP and discusses input and output requirements. The application to several case studies is presented. A complete code listing is given in the appendix, as are some sample computations. In Part C, an analytical model is developed to predict the transient performance of shallow, vertically mixed cooling ponds. This model is suggested as an aid in the initial design or screening process, eliminating the need for repeated use of MITEMP for long term simulations. When a candidate design(s) is selected, its long term performance can be analyzed with the more precise MITEMP.Prepared under the support of: Commonwealth Edison Company, Chicago, Illinois; NUS Corporation, Rockville, Maryland; Environmental Control Technology Division, U.S. Department of Energy; and Electric Power Research Institute, Palo Alto, Californi

Simultaneous multiple allelic replacement in the malaria parasite enables dissection of PKG function.

Over recent years, a plethora of new genetic tools has transformed conditional engineering of the malaria parasite genome, allowing functional dissection of essential genes in the asexual and sexual blood stages that cause pathology or are required for disease transmission, respectively. Important challenges remain, including the desirability to complement conditional mutants with a correctly regulated second gene copy to confirm that observed phenotypes are due solely to loss of gene function and to analyse structure-function relationships. To meet this challenge, here we combine the dimerisable Cre (DiCre) system with the use of multiple lox sites to simultaneously generate multiple recombination events of the same gene. We focused on the Plasmodium falciparum cGMP-dependent protein kinase (PKG), creating in parallel conditional disruption of the gene plus up to two allelic replacements. We use the approach to demonstrate that PKG has no scaffolding or adaptor role in intraerythrocytic development, acting solely at merozoite egress. We also show that a phosphorylation-deficient PKG is functionally incompetent. Our method provides valuable new tools for analysis of gene function in the malaria parasite

Comment on "A praxis-oriented perspective of streamflow inference from stage observations – the method of Dottori et al. (2009) and the alternative of the Jones Formula, with the kinematic wave celerity computed on the looped rating curve" by Koussis (2009)

The estimation of transient streamflow from stage measurements is indeed important and the study of Dottori, Martina and Todini (2009) (henceforth DMT) is useful, however, DMT seem to miss certain of its &lt;i&gt;practical aspects&lt;/i&gt;. The goal is &lt;i&gt;to infer the discharge from measurements of the stage conveniently and with accuracy adequate for practical work&lt;/i&gt;. This comment addresses issues of the applicability of the DMT method in the field. DMT also advocate their method as a replacement of the widely used Jones Formula. The Jones Formula was modified by Thomas (Henderson, 1966) to include the temporal derivative of the depth, instead of the spatial one, to specifically allow discharge estimation from at-a-section stage observations. The outcome of the comparison is not surprising in view of this approximation. However, this discussion intends to show that, properly evaluated, the praxis-oriented Jones Formula, which did well in the tests, can perform better than DMT imply. It will be also documented that the DMT methodology relates to a known method for computing flood depth profiles

Distinct effects of HIV protease inhibitors and ERAD inhibitors on zygote to ookinete transition of the malaria parasite

In an effort to eradicate malaria, new interventions are proposed to include compound/vaccine development against pre-erythrocytic, erythrocytic and mosquito stages of Plasmodium. Drug repurposing might be an alternative approach to new antimalarials reducing the cost and the time required for drug development. Previous in vitro studies have examined the effects of protease inhibitors on different stages of the Plasmodium parasite, although the clinical relevance of this remains unclear. In this study we tested the putative effect of three HIV protease inhibitors, two general aspartyl protease inhibitors and three AAA-p97 ATPase inhibitors on the zygote to ookinete transition of the Plasmodium parasite. Apart from the two general aspartyl inhibitors, all other compounds had a profound effect on the development of the parasites. HIVPIs inhibited zygote to ookinete conversion by 75%–90%, while the three AAA-p97 ATPase inhibitors blocked conversion by 50%–90% at similar concentrations, while electron microscopy highlighted nuclear and structural abnormalities. Our results highlight a potential of HIV protease inhibitors and p97 inhibitors as transmission blocking agents for the eradication of malaria

Buli dan Hubungannya Dengan Prestasi Akademik di Sekolah Berasrama Penuh di Kedah

The purpose of this study is to describe gangterism in relation to bullying behavior and determine its relationship with students' academic achievement in three residential schools (SBP) in Kedah. The dimensions of bullying studied are types of bullying behavior, types of bullies and victims, places where bullying frequently happened either direct or indirect bullying and bullies and victims emotions and feelings. It is also attempted to identify the relationship between dimensions of bullying behavior and students' academic achievement. The samples of study are students from Form One to Form Five of the three selected SBPs in Kedah. Descriptive analysis and Pearson Correlation (r) are used for data analysis. Results showed that bullying incidents occured mainly in the hostel, cafeteria and bathroom or toilet more frequently compared to other places. More boys and groups of boys were involved in bullying compared to girls and the occurrence is more of indirect bullying. However, there are responses indicating that direct physical bully do exist though at a low rate but this call for appropriate action before the incident is beyond the control of the authority. Result of correlation analysis showed academic achievement was not significantly related with bullying and victims of bullying. Nevertheless, a total of 77 percent of 396 respondents belong to the hogh achievers group compared to 23 percent who belong to the low achievers group