The Hoff circuit test is more specific than an incremental treadmill test to assess endurance with the ball in youth soccer players.

The assessment of aerobic endurance is important for training prescription in soccer, and is usually measured by straight running without the ball on a track or treadmill. Due to the ball control and technical demands during a specific soccer test, the running speeds are likely to be lower compared to a continuous incremental test. The aim of the present study was to compare the heart rate (HR), rating of perceived exertion (RPE) and speeds corresponding to 2.0 mmol∙L(-1), 3.5 mmol∙L(-1), lactate threshold (Dmax method) and peak lactate determined in the laboratory and in the Hoff circuit soccer-specific test. Sixteen soccer players (16±1 years) underwent two incremental tests (laboratory and Hoff circuit tests). The speeds were significantly higher in the treadmill test than on the Hoff circuit (2.0 mmol∙L(-1): 9.5±1.2 and 8.1±1.0 km∙h(-1); 3.5 mmol∙L(-1): 12.0±1.2 and 10.2±1.1 km∙h(-1); Dmax: 11.4±1.4 and 9.3±0.4 km∙h(-1); peak lactate: 14.9±1.6 and 10.9±0.8 km∙h(-1)). The HR corresponding to 3.5 mmol∙L-1 was significantly higher on the Hoff circuit compared to the laboratory test (187.5±18.0 and 178.2±17.6 bpm, respectively; P <0.001), while the RPE at the last incremental stage was lower on the Hoff circuit (P < 0.01). The speeds during the Hoff specific soccer test and the HR corresponding to 2.0 mmol∙L(-1), 3.5 mmol∙L(-1) and Dmax/threshold were different compared with the laboratory test. The present study shows that it is possible to assess submaximal endurance related variables specifically in soccer players.

Association between HLA-C*04 and American cutaneous leishmaniasis in endemic region of southern Brazil.

Leishmaniasis is a parasitic infectious disease with global repercussions. American cutaneous leishmaniasis (ACL) is endemic in southern Brazil and its pathogenesis varies according to parasite species, immune response, and host genetics. In terms of immunogenetics, many host genes, including HLA (human leukocyte antigen), could be involved in susceptibility to and protection against ACL. Accordingly, the aim of this study was to investigate the association between HLA class I genes (HLA-A, -B, and -C) and ACL in an endemic region of southern Brazil. The allele frequencies of 186 patients diagnosed with ACL and 278 healthy individuals were compared. HLA class I (HLA-A, -B, and -C) typing was carried out by PCR-SSO using Luminex technology. The results revealed an association between the HLA-C*04 allele and the patient study group, in which it appeared more frequently than in the control group [21.5 vs 13.49% (P = 0.0016 and Pc = 0.0258; OR = 1.7560; 95%CI = 1.2227-2.5240)], thereby suggesting an increased susceptibility to ACL. Additional allelic groups such as HLA-A*02, HLA-B*35, HLA-B*45, HLA-C*01, and HLA-C*15 were also implicated; however, further investigation is necessary to confirm their association with ACL. Therefore, the results obtained in this study demonstrate the involvement of HLA class I genes in the susceptibility or resistance to ACL, with significant association between HLA-C*04 and ACL susceptibility.

Risk factors associated with toxoplasmosis and toxocariasis in populations of children from nine cities in southern Brazil.

This study investigated the epidemiological factors that contribute to the seroprevalence of Toxoplasma gondii and Toxocara spp. in children from Paraná state, Brazil. Immunoglobulin G (IgG) antibodies to T. gondii were detected using indirect immunofluorescence, and IgG antibodies to Toxocara were detected using an enzyme-linked immunosorbent assay. For each individual, a questionnaire was completed that contained epidemiological and clinical data. The data analysis was performed using multiple logistic regression. Of the 544 children investigated, 3.2% presented co-infection with T. gondii and Toxocara spp. Of this total, 7.4% were positive for antibodies to T. gondii, and 25% were positive for antibodies to Toxocara spp. The presence of antibodies to Toxocara spp. increased the risk of T. gondii infection (P = 0.029). Children who were 1-8 years of age were less infected by T. gondii than those who were 9-12 years of age. The variables that influenced positivity for anti-Toxocara spp. were the origin of the children and contact with sand. Children with positive serology for Toxocara spp. presented more eosinophilia compared with those with non-reactive serology. Infection with both parasites reveals the need for preventive measures, such as guidance about modes of infection, parasite control and monitoring recreational areas.

Selection and characterization of a multivalent Salmonella phage and its production in a nonpathogenic Escherichia coli strain.

We report the selection and amplification of the broad-host-range Salmonella phage phi PVP-SE1 in an alternative nonpathogenic host. The lytic spectrum and the phage DNA restriction profile were not modified upon replication in Escherichia coli Bl21, suggesting the possibility of producing this phage in a nonpathogenic host, contributing to the safety and easier approval of a product based on this Salmonella biocontrol agent.

A Comparison between bright field and phase-contrast image analysis techniques in activated sludge morphological characterization.

Different approaches using microscopy image analysis procedures were employed for characterization of activated sludge systems. The approaches varied mainly on the type of visualization and acquisition method used for collection of data. In this context, this study focused on the comparison of the two most common acquisition methods: bright field and phase-contrast microscopy. Images were acquired from seven different wastewater treatment plants for a combined period of two years. Advantages and disadvantages of each acquisition technique and the results are discussed. Bright field microscopy proved to be more simple and inexpensive and provided the best overall results.

Dilution and magnification effects on image analysis applications in activated sludge characterization.

The properties of activated sludge systems can be characterized using image analysis procedures. When these systems operate with high biomass content, accurate sludge characterization requires samples to be diluted. Selection of the best image acquisition magnification is directly related to the amount of biomass screened. The aim of the present study was to survey the effects of dilution and magnification on the assessment of aggregated and filamentous bacterial content and structure using image analysis procedures. Assessments of biomass content and structure were affected by dilutions. Therefore, the correct operating dilution requires careful consideration. Moreover, the acquisition methodology comprising a 100× magnification allowed data on aggregated and filamentous biomass to be determined and smaller aggregates to be identified and characterized, without affecting the accuracy of lower magnifications regarding biomass representativeness.

Environmentally-friendly technology for rapid identification and quantification of emerging pollutants from wastewater using infrared spectroscopy.

The monitoring of emerging pollutants in wastewaters is nowadays an issue of special concern, with the classical quantification methods being time and reagent consuming. In this sense, a FTIR transmission spectroscopy based chemometric methodology was developed for the determination of eight of these pollutants. A total of 456 samples were, therefore, obtained, from an activated sludge wastewater treatment process spiked with the studied pollutants, and analysed in the range of 200 cm-1 to 14,000 cm-1. Then, a k-nearest neighbour (kNN) analysis aiming at identifying each sample pollutant was employed. Next, partial least squares (PLS) and ordinary least squares (OLS) modelling approaches were employed in order to obtain suitable prediction models. This procedure resulted in good prediction abilities regarding the estimation of atrazine, desloratadine, paracetamol, ß-estradiol, ibuprofen, carbamazepine, sulfamethoxazole and ethynylestradiol concentrations in wastewaters. These promising results suggest this technology as a fast, eco-friendly and reagent free alternative methodology for the quantification of emerging pollutants in wastewaters.

Advanced monitoring of high-rate anaerobic reactors through quantitative image analysis of granular sludge and multivariate statistical analysis.

Four organic loading disturbances were performed in lab-scale EGSB reactors fed with ethanol. In load disturbance 1 (LD1) and 2 (LD2), the organic loading rate (OLR) was increased between 5 and 18.5 kg COD m(-3) day(-1), through the influent ethanol concentration increase, and the hydraulic retention time decrease from 7.8 to 2.5 h, respectively. Load disturbances 3 (LD3) and 4 (LD4) were applied by increasing the OLR to 50 kg COD m(-3) day(-1) during 3 days and 16 days, respectively. The granular sludge morphology was quantified by image analysis and was related to the reactor performance, including effluent volatile suspended solids, indicator of washout events. In general, it was observed the selective washout of filamentous forms associated to granules erosion/fragmentation and to a decrease in the specific acetoclastic activity. These phenomena induced the transitory deterioration of reactor performance in LD2, LD3, and LD4, but not in LD1. Extending the exposure time in LD4 promoted acetogenesis inhibition after 144 h. The application of Principal Components Analysis determined a latent variable that encompasses a weighted sum of performance, physiological and morphological information. This new variable was highly sensitive to reactor efficiency deterioration, enclosing variations between 27% and 268% in the first hours of disturbances. The high loadings raised by image analysis parameters, especially filaments length per aggregates area (LfA), revealed that morphological changes of granular sludge, should be considered to monitor and control load disturbances in high rate anaerobic (granular) sludge bed digesters.

Monitoring of fed-batch E. coli fermentations with software sensors.

Accurate monitoring and control of industrial bioprocess requires the knowledge of a great number of variables, being some of them not measurable with standard devices. To overcome this difficulty, software sensors can be used for on-line estimation of those variables and, therefore, its development is of paramount importance. An Asymptotic Observer was used for monitoring Escherichia coli fed-batch fermentations. Its performance was evaluated using simulated and experimental data. The results obtained showed that the observer was able to predict the biomass concentration profiles showing, however, less satisfactory results regarding the estimation of glucose and acetate concentrations. In comparison with the results obtained with an Extended Kalman Observer, the performance of the Asymptotic Observer in the fermentation monitoring was slightly better.

Monitoring of activated sludge settling ability through image analysis: validation on full-scale wastewater treatment plants.

In recent years, a great deal of attention has been focused on the research of activated sludge processes, where the solid-liquid separation phase is frequently considered of critical importance, due to the different problems that severely affect the compaction and the settling of the sludge. Bearing that in mind, in this work, image analysis routines were developed in Matlab environment, allowing the identification and characterization of microbial aggregates and protruding filaments in eight different wastewater treatment plants, for a combined period of 2 years. The monitoring of the activated sludge contents allowed for the detection of bulking events proving that the developed image analysis methodology is adequate for a continuous examination of the morphological changes in microbial aggregates and subsequent estimation of the sludge volume index. In fact, the obtained results proved that the developed image analysis methodology is a feasible method for the continuous monitoring of activated sludge systems and identification of disturbances.

Quantification of pharmaceutical compounds in wastewater samples by near infrared spectroscopy (NIR).

The quantification of pollutants, as pharmaceuticals, in wastewater is an issue of special concern. Usually, typical methods to quantify these products are time and reagent consuming. This paper describes the development and validation of a Fourier transform near-infrared (FT-NIR) spectroscopy methodology for the quantification of pharmaceuticals in wastewaters. For this purpose, 276 samples obtained from an activated sludge wastewater treatment process were analysed in the range of 200 cm-1 to 14,000 cm-1, and further treated by chemometric techniques to develop and validate the quantification models. The obtained results were found adequate for the prediction of ibuprofen, sulfamethoxazole, 17ß-estradiol and carbamazepine with coefficients of determination (R2) around 0.95 and residual prediction deviation (RPD) values above four, for the overall (training and validation) data points. These results are very promising and confirm that this technology can be seen as an alternative for the quantification of pharmaceuticals in wastewater.

Stalked protozoa identification by image analysis and multivariable statistical techniques.

Protozoa are considered good indicators of the treatment quality in activated sludge systems as they are sensitive to physical, chemical and operational processes. Therefore, it is possible to correlate the predominance of certain species or groups and several operational parameters of the plant. This work presents a semiautomatic image analysis procedure for the recognition of the stalked protozoa species most frequently found in wastewater treatment plants by determining the geometrical, morphological and signature data and subsequent processing by discriminant analysis and neural network techniques. Geometrical descriptors were found to be responsible for the best identification ability and the identification of the crucial Opercularia and Vorticella microstoma microorganisms provided some degree of confidence to establish their presence in wastewater treatment plants.

Activated sludge process monitoring through in situ near-infrared spectral analysis.

The application of near infrared (NIR) spectroscopy for industrial process monitoring is achieving increasing importance over the last twenty years. In fact, the real time monitoring capacity of NIR spectroscopy is a very important feature for process monitoring, prediction and control as it allows a fast evaluation of the state of the process. However, the application of NIR spectroscopy in wastewater treatment processes is still to be explored. Although some applications of the technique for wastewater monitoring have been reported in the literature, there is still a need for more investigation related with applications, limitations and advantages of the technique when compared with other methods. An activated sludge reactor for aerobic treatment of a complex medium was monitored in situ with a NIR transflectance probe and traditional chemical parameters analysed off-line. NIR spectrophotometric data measured at the feed, reactor and settler were coupled to principal component analysis (PCA) to infer about the ability of this monitoring system to detect changes in the feed influent. The analysis of the score plots resulting from PCA permitted to identify the moments at which the perturbations occurred and to follow the consequent instability induced in the reactor till the day where the system is recuperated. The promising results obtained, suggest the interest in more detailed studies on the feasibility of NIR spectroscopy as an alternative method for monitoring and control of wastewater treatment processes.

New PLS analysis approach to wine volatile compounds characterization by near infrared spectroscopy (NIR).

This work aims to explore the potential of near infrared (NIR) spectroscopy to quantify volatile compounds in Vinho Verde wines, commonly determined by gas chromatography. For this purpose, 105 Vinho Verde wine samples were analyzed using Fourier transform near infrared (FT-NIR) transmission spectroscopy in the range of 5435 cm-1 to 6357 cm-1. Boxplot and principal components analysis (PCA) were performed for clusters identification and outliers removal. A partial least square (PLS) regression was then applied to develop the calibration models, by a new iterative approach. The predictive ability of the models was confirmed by an external validation procedure with an independent sample set. The obtained results could be considered as quite good with coefficients of determination (R2) varying from 0.94 to 0.97. The current methodology, using NIR spectroscopy and chemometrics, can be seen as a promising rapid tool to determine volatile compounds in Vinho Verde wines.

Quantitative image analysis as a diagnostic tool for identifying structural changes during a revival process of anaerobic granular sludge.

Due to unspecified operational problems, the specific acetoclastic activity (SAA) of the anaerobic granular sludge present in an industrial UASB reactor was considerably damaged (from 250 to less than 10mL CH(4)@STP/gVSS.d), significantly reducing the biogas production of that industrial unit. The hydrogenotrophic methanogenic activity exhibited a value of 600mL CH4@STP/gVSS.d, the settling velocity was 31.4+/-9.8m/h, the average equivalent diameter was 0.92+/-0.43mm, and about 70% of the VSS were structured in aggregates larger than 1mm. In order to study the recovery of the SAA, this sludge was collected and inoculated in a lab-scale expanded granular sludge blanket (EGSB) reactor. Ethanol was fed as the sole carbon source during a trial period of 106 days. Process monitoring included COD removal efficiency, methane production, and periodic determination of the specific methanogenic activity in the presence of acetate, propionate, butyrate, ethanol and H(2)/CO(2). Quantitative image analysis allowed for information to be obtained on granular fragmentation/erosion and filaments release. During the first operational period, biogas production was mainly due to the hydrogenotrophic activity. However, after 40 days, the SAA steadily increased achieving a maximum value of 183+/-13mL CH4@STP/gVSS.d. The onset of SAA recovery, granules breakdown and filaments release to the bulk occurred simultaneously. Further increase in SAA was accompanied by granular growth. In the last 25 days of operation, the size distribution was stable with more than 80% of projected area of aggregates corresponding to granules larger than 1mm (equivalent diameter). Confocal images from FISH hybridized sections of the granules showed that after SAA recovery, the granules developed an organized structure where an acidogenic/acetogenic external layer was apparent. Granular fragmentation and increase of filaments in the bulk, simultaneously with the increase in the acetoclastic activity are described for the first time and might represent a structural response of granular sludge to promote the optimal substrate uptake at minimal diffusion limitations.

Development of an image analysis procedure for identifying protozoa and metazoa typical of activated sludge system.

A procedure for the semi-automatic identification of the main protozoa and metazoa species present in the activated sludge of wastewater treatment plants was developed. This procedure was based on both image processing and multivariable statistical methodologies, leading to the use of the image analysis morphological descriptors by discriminant analysis and neural network techniques. The image analysis program written in Matlab has proved to be adequate in terms of protozoa and metazoa recognition, as well as for the operating conditions assessment.

Precision analog demodulation technique for open-loop Sagnac fiber optic gyroscopes.

This paper presents an analog technique for the demodulation of interferometric fiber optic gyroscopes signals, based on the calculation of the mean value of the negative cycles of the measured photodetector signal from sinusoidally modulated Sagnac gyroscopes. The developed signal processing circuit was implemented and tested in a laboratory, and it was possible to detect signals as low as 5 microrad. Experimental results measured in a 890 m fiber optic coil gyroscope equipped with the developed circuit showed that the proposed circuit, when compared to the widely used and mature lock-in amplifier technique, presented a 5.1 dB higher signal-to-noise ratio. The circuit is also very stable with the temperature, since a very low drift of 0.04 degrees /h degrees C was measured in a complete gyroscope system. The Brazilian research sounding rocket VSB-30 is currently being equipped with the developed demodulator circuit.

Knowledge-based fuzzy system for diagnosis and control of an integrated biological wastewater treatment process.

A supervisory expert system based on fuzzy logic rules was developed for diagnosis and control of a laboratory- scale plant comprising anaerobic digestion and anoxic/aerobic modules for combined high rate biological N and C removal. The design and implementation of a computational environment in LabVIEW for data acquisition, plant operation and distributed equipment control is described. A step increase in ammonia concentration from 20 to 60 mg N/L was applied during a trial period of 73 h. Recycle flow rate from the aerobic to the anoxic module and bypass flow rate from the influent directly to the anoxic reactor were the output variables of the fuzzy system. They were automatically changed (from 34 to 111 L/day and from 8 to 13 L/day, respectively), when new plant conditions were recognised by the expert system. Denitrification efficiency higher than 85% was achieved 30 h after the disturbance and 15 h after the system response at an HRT as low as 1.5 h. Nitrification efficiency gradually increased from 12 to 50% at an HRT of 3 h. The system proved to react properly in order to set adequate operating conditions that led to timely and efficient recovery of N and C removal rates.

Quantitative image analysis as a tool for Yarrowia lipolytica dimorphic growth evaluation in different culture media.

Yarrowia lipolytica, a yeast strain with a huge biotechnological potential, capable to produce metabolites such as γ-decalactone, citric acid, intracellular lipids and enzymes, possesses the ability to change its morphology in response to environmental conditions. In the present study, a quantitative image analysis (QIA) procedure was developed for the identification and quantification of Y. lipolytica W29 and MTLY40-2P strains dimorphic growth, cultivated in batch cultures on hydrophilic (glucose and N-acetylglucosamine (GlcNAc) and hydrophobic (olive oil and castor oil) media. The morphological characterization of yeast cells by QIA techniques revealed that hydrophobic carbon sources, namely castor oil, should be preferred for both strains growth in the yeast single cell morphotype. On the other hand, hydrophilic sugars, namely glucose and GlcNAc caused a dimorphic transition growth towards the hyphae morphotype. Experiments for γ-decalactone production with MTLY40-2P strain in two distinct morphotypes (yeast single cells and hyphae cells) were also performed. The obtained results showed the adequacy of the proposed morphology monitoring tool in relation to each morphotype on the aroma production ability. The present work allowed establishing that QIA techniques can be a valuable tool for the identification of the best culture conditions for industrial processes implementation.

Ability of immunodiagnostic tests to differentiate between dogs naturally infected with Leishmania infantum and Leishmune(®)-vaccinated dogs.

Visceral leishmaniasis (VL) is a serious chronic disease with a lethality rate of up to 10% in humans. In urban areas of Brazil, dogs are the main reservoirs of the etiological agent (Leishmania infantum) of VL, and the Brazilian Ministry of Health recommends the euthanasia of animals that are seropositive in both the immunochromatographic dual path platform rapid test (DPP(®); Bio-Manguinhos) and the enzyme-linked immunosorbent assay (ELISA) with an L. major-like antigen (Bio-Manguinhos). Vaccination is an additional tool in the control of canine VL, but the use of Leishmune(®) (Zoetis Indústria de Produtos Veterinários, São Paulo, SP, Brazil), which contains the fucose mannose ligand (FML) isolated from L. donovani, is not currently recommended by the Brazilian Ministry of Health because vaccinated animals may exhibit positive serology and there are reservations regarding the efficacy of the vaccine. The aims of the present study were: (i) to verify the abilities of the fast agglutination screening test (FAST), the direct agglutination test (DAT), the indirect fluorescent-antibody test (IFAT), the DPP rapid test, and ELISA tests with L. major-like and FML antigens to differentiate between L. infantum-infected and Leishmune(®)-vaccinated dogs, and (ii) to analyze the sensitivities and specificities of the different methods. The reactivities to these tests of Leishmune(®)-vaccinated dogs (n = 71), asymptomatic (n = 20) and symptomatic (n = 20) naturally infected dogs, and unvaccinated healthy control dogs (n = 5) were compared. None of the Leishmune(®)-vaccinated dogs tested seropositive in FAST and DAT, although one dog was reactive to DPP and four dogs to ELISA/L. major-like and IFAT tests. While 69 (97%) of vaccinated dogs reacted to ELISA/FML, only one was seropositive in both ELISA/L. major-like and IFAT tests. Individually, all immunodiagnostic tests presented high specificities and positive likelihood ratios (LR+), and high specificity values were obtained when the tests were considered in pairs. However, sensitivity and LR- values were low for ELISA/L. major-like and IFAT tests individually, and for all pair combinations of tests except for FAST with DPP.