Comparative Analysis of the Diagonal Stride Technique during Roller Skiing and On-Snow Skiing in Youth Cross-Country Skiers.

Roller skiing is one primary form of training method as it is an off-snow equivalent to cross-country (XC) skiing during the dry land preseason training, but the results could only be applied to on-snow skiing with appropriate caution. The aim of this present study was to investigate the similarities and differences in roller skiing and on-snow skiing with the diagonal stride (DS) technique. Six youth (age: 14.3 ± 2.9 years) skiers participated in this study. Two high-definition video camcorders and FastMove 3D Motion 2.23.3.3101 were used to obtain the three-dimensional kinematic data. The cycle characteristics and joint angle ROM of the DS technique while skiing on different surfaces were similar. Almost all joint angle-time curves that were obtained from roller skiing showed a moderate-to-high degree of similarity to the angle-time curves obtained from on-snow skiing, except the hip adduction-abduction angle. The differences between roller skiing and on-snow skiing were mainly found in the body and calf anteversion angles, and the joint angles at critical instants. DS roller skiing can simulate DS on-snow skiing to a large extent in youth athletes. The hip movement, knee flexion, and calf anteversion at ski/roller ski touchdown and take-off, pole inclination at pole touchdown, body anteversion angle, and trunk anteversion angle at pole touchdown were the points that required caution when transferring preseason practice roller skiing to on-snow skiing.

Visualizing profitability: A heatmap approach to evaluate Bitcoin futures trading using VMA trading rules.

Given that technical trading charts are publicly available on popular financial websites such as Bloomberg and MarketWatch, it stands to reason that the same technical trading approaches may be applied to cryptocurrency markets. One of these trading strategies is the variable length moving average (VMA), whose flexibility benefit has not been fully explored in prior research. To fill this gap, we evaluate Bitcoin futures using VMA trading rules and provide the results in a heatmap diagram. This approach allows investors to choose the most effective VMA rules, potentially leading to profits. Furthermore, our approach may shed new light on previously unexplored investment thinking and practices that have the potential to improve investment outcomes.

Privacy-Preserving Blockchain Technologies.

The main characteristics of blockchains, such as security and traceability, have enabled their use in many distinct scenarios, such as the rise of new cryptocurrencies and decentralized applications (dApps). However, part of the information exchanged in the typical blockchain is public, which can lead to privacy issues. To avoid or mitigate these issues, some blockchains are applying mechanisms to deal with data privacy. Trusted execution environments, the basis of confidential computing, and secure multi-party computation are two technologies that can be applied in that sense. In this paper, we analyze seven blockchain technologies that apply mechanisms to improve data privacy. We define seven technical questions related to common requirements for decentralized applications and, to answer each question, we review the available documentation and gather information from chat channels. We briefly present each blockchain technology and the answers to each technical question. Finally, we present a table summarizing the information and showing which technologies are more prominent.

Technical and locomotor demands in elite soccer: manipulating area per player during small-sided games to replicate official match demands.

The present study aimed to investigate the area per player (ApP) to replicate the technical and locomotor match demands using small-sided games (SSGs) in male soccer players (n = 20) competing in major European and UEFA competitions. The relative number of each individual technical activity per minute (number · min-1; technical demands) was counted and the relative (m · min-1) total (TD), high-speed running (HSRD), very high-speed running (VHSRD), sprint and acceleration+deceleration (Acc+Dec) distances were collected during different SSG formats (n = 24; 4 vs 4 to 10 vs 10 with an ApP from 60 to 341 m2 · player-1) and official matches (n = 28). Data were collected during two full seasons. A linear mixed model analysis was used to calculate the individual relationship between technical/locomotor demands and the ApP during SSGs; the correlation coefficient was also calculated. With the exception of an inverse moderate (r = -0.457) correlation for Acc+Dec, each locomotor metric (TD, HSRD, VHSRD and sprint) showed a positive large to very large (r = 0.560 to 0.710) correlation with ApP (P < 0.001). The technical demands showed an inverse moderate correlation (r = -0.529) with ApP. Additionally, inverse moderate to large correlations (r = -0.397 to -0.600; P < 0.05) between the technical demands and the locomotor demands (TD, HSR, VHSR and sprint) were found. Lastly, an ApP of ~243 m2 · player was found to replicate the official match technical demand and it was quite similar to the ApP required to replicate HSRD, VHSRD and sprint. These findings may help practitioners to replicate, overload and underload both technical and locomotor demands using a specific ApP during SSGs in elite soccer.

Stock market optimization amidst the COVID-19 pandemic: Technical analysis, K-means algorithm, and mean-variance model (TAKMV) approach.

The Philippine stock market, just like most of its neighbors in the region, was seriously impacted by the global pandemic COVID-19. Investors remain hopeful while continuing to seek great ones in the damaged market. This paper developed a methodology for portfolio selection and optimization with the use of technical analysis, machine learning techniques, and portfolio optimization model. The combined methods of technical analysis, K-means clustering algorithm, and mean-variance portfolio optimization model will result in the development of the proposed TAKMV method. The study aims to integrate these three important analyses to identify portfolio investments. This paper uses the average annual risk and annual rate of return data for the years 2018 and 2020 to form the clusters and assessed the stocks that correspond to the investor's technical strategy such as Moving Average Convergence/Divergence (MACD) and Hybrid MACD with Arnaud Legoux Moving Average (ALMA). This paper solved the risk minimization problem on selected shares of the companies, based on the mean-variance portfolio optimization model. There are 230 and 239 companies for 2018 and 2020, respectively, listed in Philippine Stock Market, and all simulations were performed in MATLAB environment platform. Results showed that MACD strategy dominates the MACD-ALMA strategy in terms of the number of assets with a positive annual rate of return. The MACD works efficiently in the pre-COVID-19 condition while MACD-ALMA works efficiently during-COVID-19 condition, regardless of the number of assets with a positive annual rate of return. The results also show that the maximum expected portfolio return (RP) can be achieved using the MACD and MACD-ALMA in the pre-and during-COVID-19 conditions, respectively. The MACD-ALMA shows an advantage during high-risk market conditions and can also provide maximum RP. The performance of the TAKMV method was validated by applying its results and comparing it to the next year's historical price. The 2018 results were compared to 2019 data and the 2020 results were compared to 2021 data. For consistency, the comparison was applied to the same company per portfolio. Simulation results show that the MACD strategy is more effective compared to MACD-ALMA.

Effectiveness of the Relative Strength Index Signals in Timing the Cryptocurrency Market.

In 2020 and 2021, the cryptocurrency market attracted millions of new traders and investors. Lack of regulation, high liquidity, and modern exchanges significantly lowered the entry threshold for new market participants. In 2021, over 5 million Americans were regularly involved in cryptocurrency trading. At that time, the interest in market indicators and trading strategies remained low, leading to the conclusion that most investors did not use decision-support indicators. The correct and backtested use of technical analysis signals can give the trader a significant advantage over most market participants. This work introduces an algorithmic approach to examining the effectiveness of the signals generated by one of the most popular market indicators, the Relative Strength Index (RSI). A model corresponding to an actual cryptocurrency exchange was used to backtest the strategies. The results show that the RSI as a momentum indicator in the cryptocurrency market involves high risk. Using alternative RSI applications can allow traders to gain an advantage in the cryptocurrency market. Comparing the results with the traditional buy and hold strategy shows the credible potential of the indicated method and the usage of signals generated by the technical analysis indicators.

An adaptive particle swarm optimization-based hybrid long short-term memory model for stock price time series forecasting.

In this paper, we presented a long short-term memory (LSTM) network and adaptive particle swarm optimization (PSO)-based hybrid deep learning model for forecasting the stock price of three major stock indices such as Sensex, S&P 500, and Nifty 50 for short term and long term. Although the LSTM can handle uncertain, sequential, and nonlinear data, the biggest challenge in it is optimizing its weights and bias. The back-propagation through time algorithm has a drawback to overfit the data and being stuck in local minima. Thus, we proposed PSO-based hybrid deep learning model for evolving the initial weights of LSTM and fully connected layer (FCL). Furthermore, we introduced an adaptive approach for improving the inertia coefficient of PSO using the velocity of particles. The proposed method is an aggregation of adaptive PSO and Adam optimizer for training the LSTM. The adaptive PSO attempts to evolve the initial weights in different layers of the LSTM network and FCL. This research also compares the forecasting efficacy of the proposed method to the genetic algorithm (GA)-based hybrid LSTM model, the Elman neural network (ENN), and standard LSTM. Experimental findings demonstrate that the suggested model is successful in achieving the optimum initial weights and bias of the LSTM and FC layers, as well as superior forecasting accuracy.

Concept design, technical performance, and GHG emissions analysis of petroleum coke direct chemical looping hydrogen highly integrated with gasification for methanol production process.

Petroleum coke gasification for methanol production process has excellent application prospects for the clean utilization of high­sulfur coke while limiting pollutant emissions from coke combustion. However, the process still suffers from high-energy use and a large CO2 generation caused by composition adjustment. This study proposes a novel petroleum coke chemical looping hydrogen-assisted gasification process for methanol production. Mass-energy coupling is realized by replacing the water gas shift unit with the chemical looping hydrogen unit, and the high temperature gasified gas heats the fuel reactor and in turn the feedstock. Two chemical looping hydrogen scenarios with an operating pressure of 3.0 and 0.1 MPa are considered. The methanol exergy can be increased from 484 to 1030 and 1028 MW by doubling the petroleum coke consumption through the chemical looping integration. The exergy efficiency of the new process is correspondingly increased from 51.6 to 57.1 and 55.2 % with 63.02 and 63.71 % reductions in direct CO2 emissions, as compared to the only gasification route. The calculated life cycle energy consumption and greenhouse gases emissions of the new processes are 40.02/43.84 GJ/t and 693/1055 kg CO2 eq/t, 15.14/7.05 % and 49.09/22.45 % lower than that of the benchmark process. The integration of high-pressure chemical looping technology can introduce significant technical and environmental benefits for methanol production from the petroleum coke.

Development of a stock trading system based on a neural network using highly volatile stock price patterns.

This paper proposes a pattern-based stock trading system using ANN-based deep learning and utilizing the results to analyze and forecast highly volatile stock price patterns. Three highly volatile price patterns containing at least a record of the price hitting the daily ceiling in the recent trading days are defined. The implications of each pattern are briefly analyzed using chart examples. The training of the neural network was conducted with stock data filtered in three patterns and trading signals were generated using the prediction results of those neural networks. Using data from the KOSPI and KOSDAQ markets, It was found that that the proposed pattern-based trading system can achieve better trading performances than domestic and overseas stock indices. The significance of this study is the development of a stock price prediction model that exceeds the market index to help overcome the continued freezing of interest rates in Korea. Also, the results of this study can help investors who fail to invest in stocks due to the information gap.

Middle meningeal artery embolization for treatment of chronic subdural hematomas: does selection of embolized branches affect outcomes?

OBJECTIVE: Middle meningeal artery (MMA) embolization (MMAE) is a new therapeutic modality for chronic subdural hematoma (cSDH). There is limited evidence comparing various MMAE procedural techniques, resulting in significant variations in technique and procedural planning. The objective of this study was to compare outcomes of MMAE by the number and location of MMA branches that were embolized. METHODS: A single-center retrospective study of patients with cSDH treated by MMAE was conducted. Clinical outcomes, need for re-intervention, and changes in hematoma size were compared between different MMAE techniques. RESULTS: Ninety-four cSDHs in 78 patients were included. Embolization of the proximal trunk only, distal branches only, or proximal trunk plus distal branches resulted in similar rates of need for rescue surgery (7.4%, 13.0%, and 6.8%, respectively; p = 0.66) and rates of reducing the volume of the hematoma by at least 50% (74.1%, 80.0%, and 77.5%, respectively; p = 0.88). Embolization of only one branch had similar outcomes to embolization of more than one branch, as rescue surgery rates were 9.3% and 7.8% (p = 0.80), and rates ≥ 50% volume reduction were 75.6% and 78.3% (p = 0.76), respectively. Selective embolization of the dominant MMA branch was not associated with significantly different outcomes. CONCLUSIONS: Outcomes of distal, proximal, or combined proximal and distal MMAE in cSDH are not significantly different. Embolization of more than one branch is not associated with improved treatment efficacy. Arguably, targeting any location in the MMA provides sufficient flow restriction to enable spontaneous hematoma resolution. Accordingly, a technical planning algorithm for cSDH MMAE is suggested.

Integral evaluation of granular activated carbon at four stages of a full-scale WWTP deodorization system.

Odor emissions from wastewater treatment plants (WWTPs) have always been a public concern. In this work, the physico-chemical, olfactometric and textural characterization of granular active carbon (GAC) used by an urban WWTP as a deodorization system, as well as the chromatographic quantification of the retained odoriferous compounds, have been carried out. These techniques have allowed an integral evaluation of the contaminated GAC and the characterization of the retained gaseous emission from four different stages of the wastewater treatment (pretreatment header: GAC-1; sand and fat removal: GAC-2; sludge thickening: GAC-3; sludge dehydration: GAC-4). A larger amount and variety of retained odoriferous compounds were found in GAC samples from the wastewater line deodorization (GAC-1 and GAC-2) after the same operation time (one year), GAC-1 being the adsorbent bed that retained the highest mass of volatile compounds (approximately 150µg/g GAC). Furthermore, some variables such as the removed specific odor concentration and free micropore volume were inversely correlated (R2=0.9945). The analysis of odor contribution showed that sulfur-containing compounds were the major odor contributors (61-97%). However, hydrogen sulfide cannot be considered a key odorant in this particular WWTP, since the elimination of this compound does not reduce the significant contribution of other (organic) sulfur compounds to the global odor (especially dimethyl disulfide). Consequently, multi-technical analysis might be a suitable alternative to better understand odor removal by GAC adsorption.

The Effect of Vision Impairment on Competitive and Technical-Tactical Performance in Judo: Is the Present System Legitimate?

In judo competition for visual impairment, athletes of different classes compete against each other in the same category; B1 athletes are totally blind, whereas B2 and B3 athletes are partially sighted. To test for potential competition disparities due a single category of athletes, this study aimed to compare competitive and technical-tactical performance in visually impaired judo athletes with different degrees of visual impairment. The authors analyzed 340 judo matches from the 2012 and 2016 Paralympic Games. The scores, penalties, efficiency index, and types of medals were examined, as well as the technical variation and temporal structure. The main finding was that blind judo athletes presented lower scores (p < .05; effect size [ES] = 0.43-0.73), medals (p < .05), and efficiency (p < .05; ES = 0.40-0.73); different patterns of play; and a shorter time to lose than partially sighted athletes (p = .027; ES = 0.10-0.14). However, the penalties were similar between classes (p > .05; ES = 0.07-0.14). The odds ratio of a winning medal was 3.5-8 times less in blind athletes than in partially sighted athletes (p < .01). In conclusion, blind judo athletes presented lower competitive and technical-tactical performance than athletes with some residual functional vision. These findings provide support for the development of new evidence-based criteria for judo classification based on vision impairment.

An Analysis Model for Studying the Determinants of Throwing Scoring Actions During Standing Judo.

In judo, the attacking system is grounded on several determinants of the chances to throw. In our study, data regarding four determinants of the attacking system were collected in order to classify the standing scoring actions: the attacking type (direct/counter-attack), the throwing area (forward/backward), the technique's category (based on motor criteria), and the lateral structure of fighting (contenders with a symmetrical/asymmetrical position). To study the usefulness of such an analysis, the standing scoring actions of the 2013 Judo World Championship were analyzed as an example of elite judo's attacking system (n = 775). The Pearson's chi-squared test and Cramér's V were used to analyze the hypothesis of a uniform distribution or the association between variables and the strength of such an association, respectively. The scoring actions (p < 0.001) were mostly direct attacks (82.6%), in the forward throw area (57.5%), and in an asymmetrical position (67.2%). All of the variables were associated (p < 0.05; V = 0.11⁻0.54), with higher proportions of counter-attacks and attacks occurring on the backward thrown area during asymmetrical structures than the expected. Some categories of techniques were observed more than expected, depending on the symmetrical or asymmetrical structure. Our data augment the knowledge of standing judo by showing features of the attacking system, suggesting strategies for optimizing performance.

A Socio-Technical Analysis of Patient Accessible Electronic Health Records.

In Sweden, and internationally, there is a movement towards increased transparency in healthcare including giving patients online access to their electronic health records (EHR). The purpose of this paper is to analyze the Swedish patient accessible EHR (PAEHR) service using a socio-technical framework, to increase the understanding of factors that influence the design, implementation, adoption and use of the service. Using the Sitting and Singh socio-technical framework as a basis for analyzing the Swedish PAEHR system and its context indicated that there are many stakeholders engaged in these types of services, with different driving forces and incentives that may influence the adoption and usefulness of PAEHR services. The analysis was useful in highlighting important areas that need to be further explored in evaluations of PAEHR services, and can act as a guide when planning evaluations of any PAEHR service.

Errar menos para ganhar mais: uma análise no badminton / Fewer mistakes for more winning: a badminton analysis

Um recurso muito utilizado por técnicos e atletas no badminton é a análise estatística dos componentes do jogo, a fim de minimizar os erros e otimizar os acertos e, com isso, obter o melhor rendimento do atleta. Assim, o objetivo deste estudo foi analisar a relação entre pontos vencedores (PV) e erros não forçados (ENF) com a vitória e derrota em jogos de badminton das categorias simples masculina e feminina. Foram analisados 56 jogos de simples masculino e 23 femininos durante os torneios nacionais e estaduais no ano de 2012. A pontuação final, a quantidade de PV e de ENF foram coletados em tempo real. A comparação entre a quantidade de PV e ENF em jogos com vitória e derrota, e entre os gêneros, foi feita através do Teste T para amostras independentes. Nos jogos masculinos, verificou-se a média de ENF de 13,37±6,08 e de PV 12,89±5,37. Já no feminino, a média de ENF foi 13,87±5,97 e de PV 9,43±5,07. Não foram verificadas diferenças significativas na quantidade de ENF e PV entre os gêneros. A média dos ENF em jogos perdidos, 16,3±6,4, foi significativamente maior do que nos jogos com vitória, 11,7±5,0 (p<0,01). Os PV ocorreram mais em jogos com vitória, 13,5±5,2, do que em jogos com derrota, 9,38±5,0 (p<0,01). Conclui-se que para chegar à vitória é importante que o atleta aumente o número de PV e diminua a quantidade de ENF, independente do gênero. Neste sentido, quanto melhor o atleta estiver do ponto de vista técnico, tático, físico e psicológico, melhor será sua percepção de competência, maior a superação de desafios e, consequentemente, maiores chances de acertos terá...(AU)

Coaches and athletes in badminton are using statistics analysis of the components of the game in order to minimize errors and optimize winning shots and thereby get a better overall performance of the athlete. The purpose of this study was to analyze the relationship between winners points (WP) and unforced errors (UE) with victory and defeat in male and female (single) badminton matches. We analyzed 56 male simple games and 23 women's singles during national and state tournaments of 2012. The final score, the amount of WP and UE were collected during the game. The comparison between the amount of WP and UE in games with victory and defeat, and according to gender, was performed using the unpaired T Test. In male games, we found an average of 13.37 ± 6.08 UE and 12.89 ± 5.37 WP. In women, the average was 13.87 ± 5.97 for UE and 9.43 ± 5.07 for WP. No significant differences were observed in the amount of UE and WP for gender. The average of UE in lost games (16.3 ± 6.4) was significantly higher than in the win games (11.7 ± 5.0) (p <0.01). The WP were higher in won games, 13.5 ± 5.2, than in defeated games, 9.38 ± 5.0 (p <0.01).We conclude that to achieve victory, it is important that the athlete increase the number of WP and decrease the amount of UE, regardless of the gender. The better the athlete is from a technical point of view, tactical, physical and psychological, the better their perception of competence, greater overcoming challenges and hence greater chances of success will be....(AU)

Stability of behaviour patterns in the 200m breaststroke / Estabilidade dos padrões comportamentais nos 200m do nado peito

Abstract The aim of this study was to analyse the stability of the breaststroke technique in five elite swimmers in a 200m event using a qualitative analysis. The codification of the behaviour of each swimmer during the execution of 20 cycles was achieved using an ad hoc observational instrument comprised of a system of categories and field formats to detect the behavioural patterns (T-patterns); software was used for identifying the technical behaviour of stable structures. The results showed that the stability behaviour varied depending on the swimmer, as the variations of codes in each round produced distinct configurations to determine the differences between cycles for the same swimmer. It was concluded that the instrument used in this study plays an important role through the existence of stable behaviour in the breaststroke technique. It was also concluded that there are distinct patterns and behaviours between swimmers during each lap of the race.

Resumo O objetivo deste estudo foi analisar a estabilidade da técnica de bruços em cinco nadadores de elite numa prova de 200m usando uma análise qualitativa. A codificação do comportamento de cada nadador durante a execução de vinte ciclos de nado foi alcançado usando um instrumento de observação ad-hoc composto por um sistema de categorias e formatos de campo para detectar os padrões comportamentais (T-patterns); o software foi utilizado para identificar o comportamento técnico de estruturas estáveis. Os resultados indicaram que o comportamento da estabilidade dos nadadores variou de acordo com o nadador, como as variações de códigos em cada ronda produzido configurações distintas para determinar as diferenças entre os ciclos para o mesmo nadador. Concluiu-se que o instrumento utilizado neste estudo desempenha um papel importante, através da existência de um comportamento estável na técnica de nado de peito. Concluiu-se também que existem padrões distintos e comportamentos entre nadadores durante cada percurso de nado.

Manipulation of exercise to rest ratio within set duration on physical and technical outcomes during small-sided games in elite youth soccer players.

Training practices for elite soccer players should take into account specific technical, tactical and physical components. As a consequence of these demands small-sided games (SSGs) have become a popular conditioning tool that replicate the demands encountered during match play. The aim of this investigation was to examine how the manipulation of exercise to rest ratio, within the same overall duration, affected both physical and technical outcomes during SSGs in elite youth soccer. Twelve elite youth soccer players participated in three variations of eight minute 6v6 SSGs. The three variations included eight minutes continuous, 2×4min and 4×2min. Players perceived the continuous 8min block as the hardest (4.5±1.5AU), followed by the 2×4min (3.9±1.4AU) and the 4×2min (3.3±1.4AU), although no difference in mean HR or physical measures via GPS analysis between SSGs was evident. From the technical perspective, only goals scored reached significance, with post hoc analysis identifying the number of goals scored were significantly higher during the 4×2min and 2×4min SSGs compared to 8min continuous block. These results show that subjective ratings of exertion differed between conditions, but only minor technical manipulations were observed by adjusting work to rest ratios, with no significant effect on physical performance.

Performance of technical trading rules: evidence from Southeast Asian stock markets.

This paper examines the profitability of technical trading rules in the five Southeast Asian stock markets. The data cover a period of 14 years from January 2000 to December 2013. The instruments investigated are five Southeast Asian stock market indices: SET index (Thailand), FTSE Bursa Malaysia KLC index (Malaysia), FTSE Straits Times index (Singapore), JSX Composite index (Indonesia), and PSE composite index (the Philippines). Trading strategies investigated include Relative Strength Index, Stochastic oscillator, Moving Average Convergence-Divergence, Directional Movement Indicator and On Balance Volume. Performances are compared to a simple Buy-and-Hold. Statistical tests are also performed. Our empirical results show a strong performance of technical trading rules in an emerging stock market of Thailand but not in a more mature stock market of Singapore. The technical trading rules also generate statistical significant returns in the Malaysian, Indonesian and the Philippine markets. However, after taking transaction costs into account, most technical trading rules do not generate net returns. This fact suggests different levels of market efficiency among Southeast Asian stock markets. This paper finds three new insights. Firstly, technical indicators does not help much in terms of market timing. Basically, traders cannot expect to buy at a relative low price and sell at a relative high price by just using technical trading rules. Secondly, technical trading rules can be beneficial to individual investors as they help them to counter the behavioral bias called disposition effects which is the tendency to sell winning stocks too soon and holding on to losing stocks too long. Thirdly, even profitable strategies could not reliably predict subsequent market directions. They make money from having a higher average profit from profitable trades than an average loss from unprofitable ones.

Feasibility analysis of wastewater and solid waste systems for application in Indonesia.

Indonesia is one of many developing countries with a backlog in achieving targets for the implementation of wastewater and solid waste collection, treatment and recovery systems. Therefore a technical and financial feasibility analysis of these systems was performed using Indonesia as an example. COD, BOD, nitrogen, phosphorus and pathogen removal efficiencies, energy requirements, sludge production, land use and resource recovery potential (phosphorus, energy, duckweed, compost, water) for on-site, community based and off-site wastewater systems were determined. Solid waste systems (conventional, centralized and decentralized resource recovery) were analyzed according to land requirement, compost and energy production and recovery of plastic and paper. In the financial analysis, investments, operational costs & benefits and Total Lifecycle Costs (TLC) of all investigated options were compared. Technical performance and TLC were used to guide system selection for implementation in different residential settings. An analysis was undertaken to determine the effect of price variations of recoverable resources and land prices on TLC. A 10-fold increase in land prices for land intensive wastewater systems resulted in a 5 times higher TLC, whereas a 4-fold increase in the recovered resource selling price resulted in maximum 1.3 times higher TLC. For solid waste, these impacts were reversed - land price and resource selling price variations resulted in a maximum difference in TLC of 1.8 and 4 respectively. Technical and financial performance analysis can support decision makers in system selection and anticipate the impact of price variations on long-term operation. The technical analysis was based on published results of international research and the approach can be applied for other tropical, developing countries. All costs were converted to per capita unit costs and can be updated to assess other countries' estimated costs and benefits. Consequently, the approach can be used to guide wastewater and solid waste system planning in developing countries.

Effects of distance specialization on the backstroke swimming kinematics.

The purpose of the present study was to investigate different biomechanical variables of backstroke technique in swimmers specialized in different distance events, in order to investigate the capacity to modify the timing of the arm stroke when changing the swimming velocity from sub-maximal to maximal. Two 25-m backstroke trials respectively at 70% of maximum velocity (V70) and at 100% of maximum velocity (Vmax) were performed by 9 200-m distance swimmers and 9 50-m distance swimmers. Swimming velocity, stroke length, stroke rate, duration of different phases of the arm stroke and selected kinematic variables were assessed in both cases. In the 50-m distance swimmers, the duration of the propulsive phase at Vmax, expressed as a percentage of the duration of the total underwater arm stroke, increased significantly (p = 0.001) with increasing swimming velocity. Specifically, both the pull and push phases were fundamental in the increase of duration of the propulsive phase. When compared to 200-m specialists, 50-m distance swimmers seem to be more able to modify their arm stroke phases duration when increasing the swimming velocity in backstroke. Key pointsThe 50-m DS are able to find an optimal timing among the stroke phases increasing the duration of the propulsive phase.The 50-m DS, when increasing the swimming velocity, show a more efficient relationship between propulsive and non propulsive phases with respect to the 200-m DS.Both pull and push phases are key factors for increasing the duration of the propulsive phase for the 50-m DS.