Performance levels of four Latin American laboratories for the serodiagnosis of Chagas disease in Mexican sera samples

In nearly all of the previous multicentre studies evaluating serological tests for Trypanosoma cruzi infection, sera samples from Central or South American countries have been used preferentially. In this work we compared the reliability of the serological tests using Mexican sera samples that were evaluated in four independent laboratories. This included a reference laboratory in Brazil and three participant laboratories, including one in Central America and two in Mexico. The kappa index between Brazilian and Honduran laboratories reached 1.0 and the index for the Mexican laboratories reached 0.94. Another finding of this study was that the source of antigen did not affect the performance of the serological tests.

Stated versus observed performance levels in patients with chronic low back pain

This study examined the relationship between chronic low back pain (CLBP) patients' perceived (stated) levels of function and their measured (observed) performance in squatting and stair climbing activities as compared to healthy volunteers. Twenty patients with CLBP and 20 healthy subjects were asked through an interview to self-assess their ability to comfortably perform stair climbing and squatting as well as other tolerances. The subjects were then asked to perform the activities and their performance levels were recorded. Results of the t-tests and Analysis of Variance (ANOVA) procedures revealed that patients' estimate of squatting and stair climbing abilities as well as their demonstrated levels were significantly lower (p < 0.001) than those of the healthy subjects. There was a significant difference between groups in terms of the time required to perform squatting but not stair climbing. Both healthy subjects and patients with CLBP underestimated their physical capabilities. Findings indicate that the use of actual performance measurement combined with self-report of functional abilities is needed when assessing performance levels of both healthy as well as patients with CLBP.

Comparative performance of supertree algorithms in large data sets using the soapberry family (Sapindaceae) as a case study.

For the last 2 decades, supertree reconstruction has been an active field of research and has seen the development of a large number of major algorithms. Because of the growing popularity of the supertree methods, it has become necessary to evaluate the performance of these algorithms to determine which are the best options (especially with regard to the supermatrix approach that is widely used). In this study, seven of the most commonly used supertree methods are investigated by using a large empirical data set (in terms of number of taxa and molecular markers) from the worldwide flowering plant family Sapindaceae. Supertree methods were evaluated using several criteria: similarity of the supertrees with the input trees, similarity between the supertrees and the total evidence tree, level of resolution of the supertree and computational time required by the algorithm. Additional analyses were also conducted on a reduced data set to test if the performance levels were affected by the heuristic searches rather than the algorithms themselves. Based on our results, two main groups of supertree methods were identified: on one hand, the matrix representation with parsimony (MRP), MinFlip, and MinCut methods performed well according to our criteria, whereas the average consensus, split fit, and most similar supertree methods showed a poorer performance or at least did not behave the same way as the total evidence tree. Results for the super distance matrix, that is, the most recent approach tested here, were promising with at least one derived method performing as well as MRP, MinFlip, and MinCut. The output of each method was only slightly improved when applied to the reduced data set, suggesting a correct behavior of the heuristic searches and a relatively low sensitivity of the algorithms to data set sizes and missing data. Results also showed that the MRP analyses could reach a high level of quality even when using a simple heuristic search strategy, with the exception of MRP with Purvis coding scheme and reversible parsimony. The future of supertrees lies in the implementation of a standardized heuristic search for all methods and the increase in computing power to handle large data sets. The latter would prove to be particularly useful for promising approaches such as the maximum quartet fit method that yet requires substantial computing power.

Performance Based Specifications, TR-403, 1998

The goal in highway construction and operation has shifted from method based specifications to specifications relating desired performance attributes to materials, mix designs, and construction methods. Shifting from method specifications to performance based specifications can work as an incentive or disincentive for the contractor to improve performance or extend pavement life. This literature search was directed at a review of existing portland cement concrete performance specification development, and the criteria that can effectively measure pavement performance. The criteria identified in the literature include concrete strength, slab thickness, air content, initial smoothness, water-cement ratio, unit weight, and slump. A description of each criterion, along with the advantages, disadvantages, and test methods for each are identified. Also included are the results from a survey that was sent out to various state, federal, and trade agencies. The responses indicated that 53% currently use or are developing a performance based specification program. Of the 47% of agencies that do not use a performance based specification program, over 34% indicated that they would consider a similar program. The most commonly measured characteristics include thickness, strength, smoothness, and air content. Lastly recommendations and conclusions are made regarding other factors that affect pavement performance and a proposed second phase of the research is suggested. The research team suggests that a regional expert task group be formed to identify performance levels and criteria. The results of that effort will guide the research team in the development of new or revised specifications.

Adolescent girls and mathematics: classroom performance, attitudes toward mathematics and perceptions of parental attitudes /

The purpose of this study was to determine the extent to which gender differences exist in student attitudes toward mathematics and in their performance in mathematics at the Grade Seven and Eight level. The study also questioned how parents influence the attitudes of this grade level of male and female students toward mathematics. Historically, the literature has demonstrated gender differences in the attitudes of students toward mathematics, and in parental support for classroom performance in mathematics. This study was an attempt to examine these differences at one senior public school in the Peel Board of Education. One hundred three Grade Seven and Eight students at a middle school in the Peel Board of Education volunteered to take part in a survey that examined their attitudes toward mathematics, their perceptions of their parents' attitudes toward mathematics and support for good performance in the mathematics classroom, parental expectations for education and future career choices. Gender differences related to performance levels in the mathematics classroom were examined using Pearson contingency analyses. Items from the survey that showed significant differences involved confidence in mathematics and confidence in writing mathematics tests, as well as a belief in the ability to work on mathematics problems. Male students in both the high and low performance groups demonstrated higher levels of confidence than the females in those groups. Female students, however, indicated interest in careers that would require training and knowledge of higher mathematics. Some of the reasons given to explain the gender differences in confidence levels included socialization pressures on females, peer acceptance, and attribution of success. Perceived parental support showed no significant differences across gender groups or performance levels. Possible explanations dealt with the family structure of the participants in the study. Studies that, in the past, have demonstrated gender differences in confidence levels were supported by this study, and discussed in detail. Studies that reported on differences in parental support for student performance, based on the gender of the parent, were not confirmed by this study, and reasons for this were also discussed. The implications for the classroom include: 1) build on the female students' strengths that will allow them to enjoy their experiences in mathematics; 2) stop using the boys as a comparison group; and 3) make students more aware of the need to continue studying mathematics to ensure a wider choice of future careers.

A study on the performance of flexible pavements on mature soil subgrades

The country has witnessed tremendous increase in the vehicle population and increased axle loading pattern during the last decade, leaving its road network overstressed and leading to premature failure. The type of deterioration present in the pavement should be considered for determining whether it has a functional or structural deficiency, so that appropriate overlay type and design can be developed. Structural failure arises from the conditions that adversely affect the load carrying capability of the pavement structure. Inadequate thickness, cracking, distortion and disintegration cause structural deficiency. Functional deficiency arises when the pavement does not provide a smooth riding surface and comfort to the user. This can be due to poor surface friction and texture, hydro planning and splash from wheel path, rutting and excess surface distortion such as potholes, corrugation, faulting, blow up, settlement, heaves etc. Functional condition determines the level of service provided by the facility to its users at a particular time and also the Vehicle Operating Costs (VOC), thus influencing the national economy. Prediction of the pavement deterioration is helpful to assess the remaining effective service life (RSL) of the pavement structure on the basis of reduction in performance levels, and apply various alternative designs and rehabilitation strategies with a long range funding requirement for pavement preservation. In addition, they can predict the impact of treatment on the condition of the sections. The infrastructure prediction models can thus be classified into four groups, namely primary response models, structural performance models, functional performance models and damage models. The factors affecting the deterioration of the roads are very complex in nature and vary from place to place. Hence there is need to have a thorough study of the deterioration mechanism under varied climatic zones and soil conditions before arriving at a definite strategy of road improvement. Realizing the need for a detailed study involving all types of roads in the state with varying traffic and soil conditions, the present study has been attempted. This study attempts to identify the parameters that affect the performance of roads and to develop performance models suitable to Kerala conditions. A critical review of the various factors that contribute to the pavement performance has been presented based on the data collected from selected road stretches and also from five corporations of Kerala. These roads represent the urban conditions as well as National Highways, State Highways and Major District Roads in the sub urban and rural conditions. This research work is a pursuit towards a study of the road condition of Kerala with respect to varying soil, traffic and climatic conditions, periodic performance evaluation of selected roads of representative types and development of distress prediction models for roads of Kerala. In order to achieve this aim, the study is focused into 2 parts. The first part deals with the study of the pavement condition and subgrade soil properties of urban roads distributed in 5 Corporations of Kerala; namely Thiruvananthapuram, Kollam, Kochi, Thrissur and Kozhikode. From selected 44 roads, 68 homogeneous sections were studied. The data collected on the functional and structural condition of the surface include pavement distress in terms of cracks, potholes, rutting, raveling and pothole patching. The structural strength of the pavement was measured as rebound deflection using Benkelman Beam deflection studies. In order to collect the details of the pavement layers and find out the subgrade soil properties, trial pits were dug and the in-situ field density was found using the Sand Replacement Method. Laboratory investigations were carried out to find out the subgrade soil properties, soil classification, Atterberg limits, Optimum Moisture Content, Field Moisture Content and 4 days soaked CBR. The relative compaction in the field was also determined. The traffic details were also collected by conducting traffic volume count survey and axle load survey. From the data thus collected, the strength of the pavement was calculated which is a function of the layer coefficient and thickness and is represented as Structural Number (SN). This was further related to the CBR value of the soil and the Modified Structural Number (MSN) was found out. The condition of the pavement was represented in terms of the Pavement Condition Index (PCI) which is a function of the distress of the surface at the time of the investigation and calculated in the present study using deduct value method developed by U S Army Corps of Engineers. The influence of subgrade soil type and pavement condition on the relationship between MSN and rebound deflection was studied using appropriate plots for predominant types of soil and for classified value of Pavement Condition Index. The relationship will be helpful for practicing engineers to design the overlay thickness required for the pavement, without conducting the BBD test. Regression analysis using SPSS was done with various trials to find out the best fit relationship between the rebound deflection and CBR, and other soil properties for Gravel, Sand, Silt & Clay fractions. The second part of the study deals with periodic performance evaluation of selected road stretches representing National Highway (NH), State Highway (SH) and Major District Road (MDR), located in different geographical conditions and with varying traffic. 8 road sections divided into 15 homogeneous sections were selected for the study and 6 sets of continuous periodic data were collected. The periodic data collected include the functional and structural condition in terms of distress (pothole, pothole patch, cracks, rutting and raveling), skid resistance using a portable skid resistance pendulum, surface unevenness using Bump Integrator, texture depth using sand patch method and rebound deflection using Benkelman Beam. Baseline data of the study stretches were collected as one time data. Pavement history was obtained as secondary data. Pavement drainage characteristics were collected in terms of camber or cross slope using camber board (slope meter) for the carriage way and shoulders, availability of longitudinal side drain, presence of valley, terrain condition, soil moisture content, water table data, High Flood Level, rainfall data, land use and cross slope of the adjoining land. These data were used for finding out the drainage condition of the study stretches. Traffic studies were conducted, including classified volume count and axle load studies. From the field data thus collected, the progression of each parameter was plotted for all the study roads; and validated for their accuracy. Structural Number (SN) and Modified Structural Number (MSN) were calculated for the study stretches. Progression of the deflection, distress, unevenness, skid resistance and macro texture of the study roads were evaluated. Since the deterioration of the pavement is a complex phenomena contributed by all the above factors, pavement deterioration models were developed as non linear regression models, using SPSS with the periodic data collected for all the above road stretches. General models were developed for cracking progression, raveling progression, pothole progression and roughness progression using SPSS. A model for construction quality was also developed. Calibration of HDM–4 pavement deterioration models for local conditions was done using the data for Cracking, Raveling, Pothole and Roughness. Validation was done using the data collected in 2013. The application of HDM-4 to compare different maintenance and rehabilitation options were studied considering the deterioration parameters like cracking, pothole and raveling. The alternatives considered for analysis were base alternative with crack sealing and patching, overlay with 40 mm BC using ordinary bitumen, overlay with 40 mm BC using Natural Rubber Modified Bitumen and an overlay of Ultra Thin White Topping. Economic analysis of these options was done considering the Life Cycle Cost (LCC). The average speed that can be obtained by applying these options were also compared. The results were in favour of Ultra Thin White Topping over flexible pavements. Hence, Design Charts were also plotted for estimation of maximum wheel load stresses for different slab thickness under different soil conditions. The design charts showed the maximum stress for a particular slab thickness and different soil conditions incorporating different k values. These charts can be handy for a design engineer. Fuzzy rule based models developed for site specific conditions were compared with regression models developed using SPSS. The Riding Comfort Index (RCI) was calculated and correlated with unevenness to develop a relationship. Relationships were developed between Skid Number and Macro Texture of the pavement. The effort made through this research work will be helpful to highway engineers in understanding the behaviour of flexible pavements in Kerala conditions and for arriving at suitable maintenance and rehabilitation strategies. Key Words: Flexible Pavements – Performance Evaluation – Urban Roads – NH – SH and other roads – Performance Models – Deflection – Riding Comfort Index – Skid Resistance – Texture Depth – Unevenness – Ultra Thin White Topping

Levels of digestible threonine for male broilers from 1 to 7 days of age

The influence of threonine has been studied in broilers; however, information concerning the phase from 1 to 7 d is lacking. In this study, we evaluated the effects on performance and body composition and the relationship with other amino acids with respect to digestible lysine and total glycine + glycine. Research on the initial 7-d phase of broiler growth is still poorly studied, even though it is important, especially in nutrition. It was found that threonine had a great influence on the broilers at that phase and nutritional recommendations need constant evaluation. In conclusion, the digestible threonine: digestible lysine ratio and digestible threonine: total glycine + serine ratio recommended for better performance and body composition are 0.68 and 0.40, respectively. The levels of digestible threonine and total glycine + serine that provide the best results are 0.864 and 2.192%, respectively.

Exploração de fatores de risco para lesões no atletismo de alta performance

Os fatores de risco para instalação de lesões do esporte têm sido pesquisados no sentido de facilitar o entendimento sobre o assunto. Contudo, para altos níveis de performance, nos eventos de pista e campo do atletismo, são escassos os documentos que abordam o tema. Assim, a partir da possibilidade de reunir informações sobre a condição descrita, objetivou-se com o presente estudo a exploração de fatores de risco para lesões desportivas no atletismo, a partir de inquérito aplicado a atletas da elite mundial da modalidade. A população foi composta por 60 homens e 60 mulheres alocados em grupos conforme a especificidade de sua modalidade (velocidade, resistência, arremessos e saltos). Realizou-se entrevista utilizando-se de inquérito de morbidade referida, abordando questões sobre variáveis antropométricas e de treinamento, assim como lesões. Utilizou-se a técnica da análise de variância paramétrica para as variáveis antropométricas (idade, peso, estatura) e da técnica da análise de variância não paramétrica em relação às variáveis de treinamento (anos de treinamento e horas semanais). Para associação entre momento de lesão e especialidades, utilizou-se do teste de Goodman em nível de 5% de significância. Os resultados mostraram que houve elevada freqüência de lesões na modalidade em ambos os sexos. As taxas de lesão por atleta entrevistado foram de 0,92 (velocidade), 1,08 (resistência), 1,22 (saltos) e 1,20 (arremessos). Não houve diferença estatisticamente significante para as variáveis antropométricas e de treinamento em relação às provas, com exceção dos saltadores, que apresentaram diferenças para estatura e tempo de treinamento; nesse caso, os acometidos são mais altos ou praticam atletismo há menos tempo (P < 0,05). Concluiu-se que, para população estudada, o risco de lesão é acentuado, mas sem relação entre variáveis e presença de agravos, salvo para especialistas em provas de saltos, que apresentaram estatura e tempo de treinamento como fatores predisponentes à lesão.

Growth performance and metabolic response of Nile tilapia fed rations supplemented with autolized yeast and zinc

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Respostas da frequência de braçada e do comprimento de braçada na e acima da intensidade correspondente à máxima fase estável de lactato sanguíneo em indivíduos com diferentes níveis de performance

The main objective of this study was to analyze the behavior of variables related to swim ability at and above maximal lactate steady state (MLSS), performed at continuous and intermittent conditions in individuals with different aerobic performance levels. Participated of this study male swimmers with ages between 20 to 25 years, specialists in events of 400 m, 800 m and 1500 m and open water swims, with at least 3 years of experience in the modality. The individuals performed a maximal 400-m swim test. After this test, they were divided into two groups, in accordance with the speed attained during 400-m swim test: G1 (higher performance) and G2 (lower performance). For the determination of continuous MLSS (MLSSc), 2 to 4 trials of 30-min were performed. For the determination of the intermittent MLSS (MLSSi) 2 to 4 trials of 30-min (12 repetitions of 2 min 30 s, with 30 s of rest) were performed, in constant speed, with the first trial performed at 102.5% MLSSc. Th technical indexes, stroke rate (FB) and stroke length (CB) were determined in all tests. The SR was calculated trough recordings using the time needed to perform five stroke cycles. The SL was calculated dividing the speed by the SR. There was no significant difference on the antropometric characteristics between groups. The speed at and above MLSSc were significantly higher at G1 (1,23±0,05 e 1,27±0,06, respectively) than G2 (1,10±0,06 e 1,13±0,06, respectively). There was significant change in SL and SR in G2. In the same way, there was significant change in SL and SR only in G2, above MLSSc. Similar to continuous condition, the speeds at and above MLSSi were significantly higher in G1 (1,27±0,05 e 1,30±0,05, respectively) do que no G2 (1,14±0,07 e 1,16±0,07, respectively). There was significant change in SL and SR only in G2. There was significant change in SR and SL in both groups above MLSSi. Thus,...(Complete abstract click electronic access below)

Flexural strengthening of reinforced concrete beams with carbon fibers reinforced polymer (CFRP) sheet bonded to a transition layer of high performance cement-based composite

Resistance to corrosion, high tensile strength, low weight, easiness and rapidity of application, are characteristics that have contributed to the spread of the strengthening technique characterized by bonding of carbon fibers reinforced polymer (CFRP). This research aimed to develop an innovate strengthening method for RC beams, based on a high performance cement-based composite of steel fibers (macro + microfibers) to be applied as a transition layer. The purpose of this transition layer is better control the cracking of concrete and detain or even avoid premature debonding of strengthening. A preliminary study in short beams molded with steel fibers and strengthened with CFRP sheet, was carried out where was verified that the conception of the transition layer is valid. Tests were developed to get a cement-based composite with adequate characteristics to constitute the layer transition. Results showed the possibility to develop a high performance material with a pseudo strain-hardening behavior, high strength and fracture toughness. The application of the strengthening on the transition layer surface had significantly to improve the performance levels of the strengthened beam. It summary, it was proven the efficiency of the new strengthening technique, and much information can be used as criteria of projects for repaired and strengthened structures.

Self-assessment insufficiently predicts performance in emergency skills

Background: Residents demonstrate a broad range of performance levels for clinical skills, with some at an inadequate level. Adequate self-assessment is important for life long learning. However, its accuracy is questioned extensively. The aim of this study was to evaluate how far the residents’ self-assessment predicts their performance in an expert assessment of emergency skills. Summary of work: Twelve skills were identified as being relevant for the emergency duties of residents in smaller hospitals. Fifteen first-year residents from the departments of internal medicine and general surgery at a district hospital rated their performance on a questionnaire (self-assessment). This was followed by a structured, practical in vivo assessment by an anaesthesiologist (expert assessment). For both, a visual analogue scale from 0 to 10 was used, on which 0 stands for novice and 10 for expert. Predictive validity was described by Spearman’s correlation, which was significant in 3 out of 12 skills only. Median correlation (r) was 0.50 (range 0.16 to 0.93). Conclusion: At the beginning of postgraduate training, self-assessment alone is not sufficient to guide self-directed learning. Take-home message: At the beginning of their residency, physicians need structured feedback in emergency skills which can be offered by anaesthesiologists.

Quality management, environmental management and firm performance in the Spanish hotel industry

Comunicación presentada en el XVI Simposio Internacional de Turismo y Ocio, ESADE, 23 mayo 2007.

Quality certification, performance and size in hotel chains

This paper examines the relationship between quality certification and performance, and quality certification and size in hotel chains operating in Spain. In an initial phase, a quantitative study is made with secondary and objective data to analyse these relationships. In a second phase, a qualitative analysis is applied to reach a better understanding of the quantitative results. The findings show that chains with certified hotels achieve better performance levels; that better performance levels increase with the percentage of certified hotels within the chain; and that quality certification has positive effects on some performance variables. In addition, size is not a key factor for certification, although it could be an enabler.

Double jeopardy:subordinates' worldviews and poor performance as predictors of abusive supervision

Purpose - To test a moderated mediation model where a positive relationship between subordinates’ perceptions of a dangerous world—the extent to which an individual views the world as a dangerous place—and supervisory abuse is mediated by their submission to authority figures, and that this relationship is heightened for more poorly performing employees. Design/Methodology/Approach - Data were obtained from 173 subordinates and 45 supervisors working in different private sector organizations in Pakistan. Findings - Our model was supported. It appears that subordinates’ dangerous worldviews are positively associated with their perceptions of abusive supervision and that this is because such views are likely to lead to greater submission to authority figures. But this is only for those employees who are performing more poorly. Implications - We highlight the possibility that individual differences (worldviews, attitudes to authority figures, and performance levels) may lead employees to become victims of abusive supervision. As such, our research informs organizations on how they may better support supervisors in managing effectively their subordinate relationships and, in particular, subordinate poor performance. Originality/Value - We add to recent work exploring subordinate-focused antecedents of abusive supervision, finding support for the salience of the previously untested constructs of individual worldviews, authoritarian submission, and individual job performance. In so doing we also extend research on dangerous worldviews into a new organizational setting. Finally, our research takes place within a new Pakistani context, adding to the burgeoning non-US based body of empirical work into the antecedents and consequences of abusive supervision.