Search

Purpose: To assess the relationship between flat-water tests and canoe slalom performance on 4 different grades of water terrain difficulty. Methods: Nineteen elite canoe slalom athletes racing in category K1 men (n = 7), K1 women (n = 5), or C1 men (n = 7) completed flat-water tests: (1) a sprint with a turn to the preferred side, (2) a sprint with a turn to the nonpreferred side, (3) a sprint with a turn to both sides, and (4) a 12 × 15-m all-out shuttle test. Canoe slalom performance was measured in competitions with 4 different grades of water terrain difficulty. Results: There were relationships between 12 × 15-m all-out shuttle test and performance across different water terrain grades (P <.001; r =.706–.871)); however, the magnitude of the relationship decreased with increasing water terrain grade difficulty. Similar trends were observed for the sprint with a turn to the preferred side (r =.588–.884), sprint with a turn to the nonpreferred side (r =.544–.864), and sprint with a turn to both sides (r =.638–.909). In addition, small to moderate differences were observed between preferred and nonpreferred side in K1 women (P =.050, ES = 0.37), K1 men (P =.019, ES = 0.66), and C1 men (P =.003, ES = 0.69). Conclusion: The novel battery of flatwater tests can be used to measure the performance-related physical fitness of canoe slalom athletes. Sprint with a turn to the preferred side and sprint with a turn to the nonpreferred side can also be used to assess the imbalance between an athlete's preferred and nonpreferred side. Accordingly, to our findings, practitioners could consider adapting the training program in preparation for important competitions specifically to water terrain difficulty grades where these competitions will be organized. [ABSTRACT FROM AUTHOR]

Abstract Background Malaria is transmitted by different Anopheles species. In Brazil, the disease is concentrated in the Amazon region. Rivers play an important role in the life cycle of malaria since the vector reproduces in aquatic environments. The waters of the rivers in the Amazon have distinct chemical characteristics, which affect the colour of the water and therefore, the study analysed whether the colour of the waters of the rivers have an on influence the distribution of malaria. The goal of the study was to correlate the different colourations of the water (black, white and mixed water) and the malaria incidence in 50 municipalities of the Amazonas state, Brazil, and then test hypotheses about the characteristics of the colour of the rivers and disease incidence. Methods This study was conducted for a period of seventeen years (2003–2019) in 50 municipalities in the state of Amazonas, Brazil. A conditionally Gaussian dynamic linear model was developed to analyse the association of malaria incidence and three types of river colour: white, black and mixed. Results The analyses indicate that the distribution of malaria is related to the colouration of the rivers. The results showed that places located near black-water rivers have a higher malaria incidence when compared to places on the banks of white-water rivers. Conclusions Historically, the hydrological regime has played an important role in the dynamics of malaria in the Amazon, but little is known about the relationship between river colours and the incidence of the disease. This research was carried out in a region with hydrographic characteristics that were heterogeneous enough to allow an analysis that contrasted different colours of the rivers and covered almost the whole of the state of Amazonas. The results help to identify the places with the highest risk of malaria transmission and it is believed that they will be able to contribute to more precise planning of actions aimed at controlling the disease in the region.

Background: Malaria is transmitted by different Anopheles species. In Brazil, the disease is concentrated in the Amazon region. Rivers play an important role in the life cycle of malaria since the vector reproduces in aquatic environments. The waters of the rivers in the Amazon have distinct chemical characteristics, which affect the colour of the water and therefore, the study analysed whether the colour of the waters of the rivers have an on influence the distribution of malaria. The goal of the study was to correlate the different colourations of the water (black, white and mixed water) and the malaria incidence in 50 municipalities of the Amazonas state, Brazil, and then test hypotheses about the characteristics of the colour of the rivers and disease incidence. Methods: This study was conducted for a period of seventeen years (2003–2019) in 50 municipalities in the state of Amazonas, Brazil. A conditionally Gaussian dynamic linear model was developed to analyse the association of malaria incidence and three types of river colour: white, black and mixed. Results: The analyses indicate that the distribution of malaria is related to the colouration of the rivers. The results showed that places located near black-water rivers have a higher malaria incidence when compared to places on the banks of white-water rivers. Conclusions: Historically, the hydrological regime has played an important role in the dynamics of malaria in the Amazon, but little is known about the relationship between river colours and the incidence of the disease. This research was carried out in a region with hydrographic characteristics that were heterogeneous enough to allow an analysis that contrasted different colours of the rivers and covered almost the whole of the state of Amazonas. The results help to identify the places with the highest risk of malaria transmission and it is believed that they will be able to contribute to more precise planning of actions aimed at controlling the disease in the region. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the test-retest reliability of four flatwater performance-related tests in canoe slalom athletes. Methods: Twenty-two Slovak national team members of junior and U23 age group racing in a category K1 men (K1M), K1 women (K1W) or C1 men (C1M) volunteered to take part in this study. During both test and retest testing sessions athletes performed 4 flatwater tests: SPS--Sprints with a turn to the preferred side (2 × 15m shuttle sprints), SNPS--Sprints with a turn to the non-preferred side (2 × 15mshuttle sprints), SBS--Sprints with turns to both sides (2 × 15mshuttle sprints) as well as 12 × 15 AOT--12 × 15m all out shuttle test (12 × 15m shuttle sprints). Each athlete completed two sessions separated by a minimum of days and a maximum of 5 days. Results: The results have shown the excellent test-retest reliability of all four flatwater tests (ICC--SPS: 0.98; SPNPS 0.97; SBS: 0.98 and 12 × 15mAOT: 0.96). Additionally, results have shown SEM (SPS: 0.14; SPNPS 0.18; SBS: 0.13 and 12 × 15mAOT: 1.05) and SWC (SPS: 0.21; SPNPS 0.26; SBS: 0.19 and 12 × 15m AOT: 1.58). Conclusion: Based on our results we suggest that coaches use these valid and reliable tests to assess changes in their athletes' performancerelated physical fitness over time, to verify the effectiveness of training programs focused on improvement in specific physical fitness of athletes as well as to identify asymmetries between the preferred and non-preferred side in canoe slalom athletes. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the test–retest reliability of four flatwater performance-related tests in canoe slalom athletes. Methods: Twenty-two Slovak national team members of junior and U23 age group racing in a category K1 men (K1M), K1 women (K1W) or C1 men (C1M) volunteered to take part in this study. During both test and retest testing sessions athletes performed 4 flatwater tests: SPS—Sprints with a turn to the preferred side (2 × 15 m shuttle sprints), SNPS—Sprints with a turn to the non-preferred side (2 × 15 m shuttle sprints), SBS—Sprints with turns to both sides (2 × 15 m shuttle sprints) as well as 12 × 15 AOT—12 × 15 m all out shuttle test (12 × 15 m shuttle sprints). Each athlete completed two sessions separated by a minimum of days and a maximum of 5 days. Results: The results have shown the excellent test-retest reliability of all four flatwater tests (ICC—SPS: 0.98; SPNPS 0.97; SBS: 0.98 and 12 × 15 m AOT: 0.96). Additionally, results have shown SEM (SPS: 0.14; SPNPS 0.18; SBS: 0.13 and 12 × 15 m AOT: 1.05) and SWC (SPS: 0.21; SPNPS 0.26; SBS: 0.19 and 12 × 15 m AOT: 1.58). Conclusion: Based on our results we suggest that coaches use these valid and reliable tests to assess changes in their athletes’ performance-related physical fitness over time, to verify the effectiveness of training programs focused on improvement in specific physical fitness of athletes as well as to identify asymmetries between the preferred and non-preferred side in canoe slalom athletes.

Copyright of Notfall & Rettungsmedizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The pulp industry is a high natural resources consumer and has a large polluting potential. The pulping sector with the most effluent generation is the bleaching plant. Based on the need of water consumption reduction, this research aimed to evaluate the treatment of the alkaline effluent from an EP-stage bleaching plant and the white water from drying machine using ultrafiltration membranes in order to enable the reuse of the permeate in the process. An ultrafiltration pilot plant was used. Laboratory analyses were performed for the feed, permeate and retentate. Flux and transmembrane pressure (TMP) data were obtained from the pilot plant database. There were an average color and COD removals of 38 % and 39 %, respectively, for the EP-effluent and 58 % and 67 %, respectively for the white water; and a high turbidity and TSS removal (above 98 %) for both effluents. Substantial metals removal such as sodium, potassium, calcium, iron, magnesium and manganese was achieved. Some possibilities to reuse were considered: return to the water treatment plant, cooling of the digester bottom, equipment cooling, reuse in evaporation surface condensers. The use of ultrafiltration for the treatment of the alkaline effluent from the bleaching EP-stage and white water can be an interesting option. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sound of a river can change from a babbling brook to a thunderous torrent, and we have previously shown that there is the potential to predict river stage from the river's sub‐aerial sound. Here, we examined how alterations in channel configuration can change the relationship between stage and sound pressure level using a white water course to simulate a real‐world scale channel. By using blocks as roughness elements (REs), we were able to customize the course's obstacles, creating towers of different heights and placements. We then ran a varied flow discharge of up to 10 m3 s−1. We used data collected from microphones, a hydrophone and cameras to monitor the flow and to understand the processes occurring. In addition to sound processing, we used image analysis to calculate the area of white water on the surface of the water to determine the mechanism for sound production. Our analysis showed the likeliest source of sub‐aerial sound is from white water being produced from the flow's interaction with the REs, with the relationship between white water value and sound relationship having an R2 between 0.35 and 0.82. In terms of influence on sound, we found that the height of the REs is more important than their spatial distribution, with the taller the RE, the better the logarithmic relationship between sound and stage. We suggest that monitoring in a natural setting will work best in the places with the tallest obstacles and that the quality of the sound‐stage relationship is dependent on RE height. Key Points: The height of an obstacle is the controlling factor on any sound‐stage relationshipMonitoring sound above the height of an obstacle is possible due to continued free‐surface effectsThe production of sub‐aerial sound is primarily produced by white water [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to determine the anthropometric and somatotype differences between elite single-canoeists (C1) included in the white-water slalom Czech national team (NT) (n = 5) and others (n = 12) who did not qualify for the national team (DNQ) leading up to the Olympic Games in Rio de Janiero, 2016. All paddlers were measured using a battery of 40 anthropometric parameters in one day, 4 weeks before competing in the Czech national selection races. The NT racers had a significantly (p < 0.05) greater circumference of the forearm (27.8 ± 0.6 vs. 26.8 ± 1.4) and upper arm (35.60 ± 1.5 vs. 33.5 ± 1.7) for the dominant paddling arm, as well as a greater chest circumference (98.3 ± 2.4 vs. 93.9 ± 2.3). Additionally, the sum of triceps, scapular, calf, and supraspinal skinfolds were significantly less in NT. There were no significant differences in height (p = 0.14), body mass (p = 0.18) or circumferences of the lower extremities (p = 0.09–0.32). Somatotype was statistically similar (p = 0.06–0.13), but practically different (NT = 1.4–5.6–2.3; DNQ = 1.6–4.6–3.1) such as body fat percentage (NT = 7.5 ± 2.3; DNQ = 9.1 ± 1.6). Based on the results of this study we can recommend that single-canoeists seeking to achieve elite performance should participate in training that focuses on maximizing the musculature of the upper limbs and chest while maintaining minimal body fat. The current data also shows that experience likely plays a role in national team selection, as NT were an average of 5.5 years older than DNQ.

Highlights • A green, blue, grey and white water footprints have been estimated for citrus at the provincial level. • The impacts of climatic and non-climatic factors have been evaluated on the variability of citrus water footprint components. • Water footprint increases when the crop yield decreases. • The water footprint depends on the non-climatic factors rather than the climatic factors. Abstract Citrus is one of the most important crops on the world and the southern part of Iran has a huge field for citrus. Exporting these products to farmers is very important economically. Shortage of water resources is the main challenge for citrus gardens. Therefore, water resources management of citrus is essential in these regions. The purpose of this paper is calculation of water footprint components of citrus production in Hormozgan province. Then, it evaluated the impacts of climatic and non-climatic factors on the variability of citrus water footprint during 2002-2016. The total water footprint of citrus was 6.69 m3 kg−1 with sharing of 2%, 16% and 82% for the green, blue and white + grey, respectively. Also the results showed crop yield is the most important factor on temporal variation of citrus water footprint. The trend of blue, grey and white water footprints is significantly increasing in 2002-2016. This research provides practical approaches for managers and policy-makers in the agriculture area for managing the water footprint and helps to optimize the water consumption and cultivation of citrus at regional scales. [ABSTRACT FROM AUTHOR]

River flow is one of the key determinants of the quality and value of white water recreational resources. However, water abstraction for activities such as irrigation and hydroelectric power generation may reduce the availability of preferred flows with consequential impacts on recreational river users. We evaluated kayaking and rafting values in the Rangitata River, Canterbury, New Zealand under the current flow regime and for a proposed additional high-flow take of 10 m3/s, on a reach between the Klondyke gauge and the Arundel Bridge. This reach is recognised for its outstanding kayaking and rafting values under the Water Conservation (Rangitata River) Order 2006. Differences in flow characteristics between the scenarios were quantified using simulations derived from a 48-year record of mean daily flow over a November to April paddling season, and hourly flow data for a fresh event. Impacts were evaluated by examining the number of days in preferred flow ranges (boatable days) for different user groups. The proposed 10 m3/s take increases boatable days for beginner and intermediate rafters (with a preferred flow range of 55-250 m³/s) and intermediate kayakers (45-170 m³/s) by 0.5 and 1.6 days (0.5% and 1.6%), respectively, perhaps suggesting a small net benefit for boaters. However, boatable days increase by 5.6 days (163%) in the 95-100 m³/s flow band by the flat-lining of flows, whilst flows > 100 m³/s reduce by 5.1 and 4.0 days (15.7% and 16.6%) for beginner and intermediate rafters, and intermediate kayakers, respectively, revealing significant negative underlying impacts. Thus, there can be drawbacks and limitations in the use of overall boatable days or changes in boatable days as the basis for quantifying abstraction impacts. It is essential that boatable days in the component flow ranges preferred by different user groups are considered and analysed in order to determine the true impact of flow takes. [ABSTRACT FROM AUTHOR]

A new formulation for the prediction of free surface dynamics related to the turbulence occurring nearby is proposed. This formulation, altogether with a breakup criterion, can be used to compute the inception of self-aeration in high velocity flows like those occurring in hydraulic structures. Assuming a simple perturbation geometry, a kinematic and a non-linear momentum-based dynamic equation are formulated and forces acting on a control volume are approximated. Limiting steepness is proposed as an adequate breakup criterion. Role of the velocity fluctuations normal to the free surface is shown to be the main turbulence quantity related to self-aeration and the role of the scales contained in the turbulence spectrum are depicted. Surface tension force is integrated accounting for large displacements by using differential geometry for the curvature estimation. Gravity and pressure effects are also contemplated in the proposed formulation. The obtained equations can be numerically integrated for each wavelength, hence resulting in different growth rates and allowing computation of the free surface roughness wavelength distribution. Application to a prototype scale spillway (at the Aviemore dam) revealed that most unstable wavelength was close to the Taylor lengthscale. Amplitude distributions have been also obtained observing different scaling for perturbations stabilized by gravity or surface tension. The proposed theoretical framework represents a new conceptualization of self-aeration which explains the characteristic rough surface at the non-aerated region as well as other previous experimental observations which remained unresolved for several decades. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the anthropometric and somatotype differences between elite single-canoeists (C1) included in the white-water slalom Czech national team (NT) (n = 5) and others (n = 12) who did not qualify for the national team (DNQ) leading up to the Olympic Games in Rio de Janiero, 2016. All paddlers were measured using a battery of 40 anthropometric parameters in one day, 4 weeks before competing in the Czech national selection races. The NT racers had a significantly (p < 0.05) greater circumference of the forearm (27.8 ± 0.6 vs. 26.8 ± 1.4) and upper arm (35.60 ± 1.5 vs. 33.5 ± 1.7) for the dominant paddling arm, as well as a greater chest circumference (98.3 ± 2.4 vs. 93.9 ± 2.3). Additionally, the sum of triceps, scapular, calf, and supraspinal skinfolds were significantly less in NT. There were no significant differences in height (p = 0.14), body mass (p = 0.18) or circumferences of the lower extremities (p = 0.09-0.32). Somatotype was statistically similar (p = 0.06-0.13), but practically different (NT = 1.4-5.6-2.3; DNQ = 1.6-4.6-3.1) such as body fat percentage (NT = 7.5 ± 2.3; DNQ = 9.1 ± 1.6). Based on the results of this study we can recommend that single-canoeists seeking to achieve elite performance should participate in training that focuses on maximizing the musculature of the upper limbs and chest while maintaining minimal body fat. The current data also shows that experience likely plays a role in national team selection, as NT were an average of 5.5 years older than DNQ. [ABSTRACT FROM AUTHOR]

The paper production process is significantly affected by direct and indirect effects of microorganism proliferation. Microorganisms can be introduced in different steps. Some microorganisms find optimum growth conditions and proliferate along the production process, affecting both the end product quality and the production efficiency. The increasing need to reduce water consumption for economic and environmental reasons has led most paper mills to reuse water through increasingly closed cycles, thus exacerbating the bacterial proliferation problem. In this work, microbial communities in a paper mill located in Italy were characterized using both culture-dependent and independent methods. Fingerprinting molecular analysis and 16S rRNA library construction coupled with bacterial isolation were performed. Results highlighted that the bacterial community composition was spatially homogeneous along the whole process, while it was slightly variable over time. The culture-independent approach confirmed the presence of the main bacterial phyla detected with plate counting, coherently with earlier cultivation studies (Proteobacteria, Bacteroidetes, and Firmicutes), but with a higher genus diversification than previously observed. Some minor bacterial groups, not detectable by cultivation, were also detected in the aqueous phase. Overall, the population dynamics observed with the double approach led us to hypothesize a possible role of suspended bacteria in the re-formation mechanisms of resistant biofilms.

Electrochemical generation of oxidants was studied to find new solutions to control microbial contamination at paper mills. Laboratory and semi-pilot trials using a Wet End Simulator indicated that the combination of an electrochemically produced halogen-containing oxidant together with sodium percarbonate was an efficient new biocide concept, especially in fine papermaking. Addition of sodium percarbonate considerably reduced the need for halogen-containing biocides, thus lessening risk of corrosion. The trials with samples from fine paper machines indicated that the new concept required halogenated biocides to be dosed first, and the time delay between additions of biocide needed to be sufficient to ensure that no residual halogen was left when sodium percarbonate was added. Electrochemical generation enables on-site biocide production, which decreases transportation cost, risk associated with storage of hazardous chemicals, and biocide lost due to degradation. Thus, on-site generation of biocides together with potential reduction in amount of halogen containing oxidants make this dual concept economically attractive and environmentally positive.

Feasibility of electrochemically generated biocides in papermaking was evaluated in pilot scale trials. The trials indicated that electrochemically generated biocides prevent microbial growth and proliferation in broke systems, as well as in water circulations. The spoilage of broke can be delayed, and already spoiled broke can be recovered using these biocides. The improved broke quality increases the stability of the paper machine and, consequently, less broke is produced. The biocides can be added to water or pulp, and they have hardly any negative effect on the process or the end product. The presence of reducing compounds may cause limitations in the use of these oxidative biocides. It was observed that electrochemically generated biocide was also efficient against heat-resistant spores. However, the biocide was less efficient against spores as compared to vegetative cells, both aerobic and anaerobic, especially when the spore numbers were higher than 104 cfu/ml. Onsite oxidant production eliminates the transportation and storage of biocides. Moreover, due to the short time between the production and use, the degradation of the active compounds can be minimized.

In white-water kayaking, the legs play a vital part in turning, stabilising and bracing actions. To date, there has been no reported information on neuromuscular activation of the legs in an authentic white-water environment. The aim of the current study was to identify lower body muscle activation, using ‘in-boat’ electromyography (EMG), whilst navigating a white-water run. Ten experienced male kayakers (age 31.5 ± 12.5 yr, intermediate to advanced experience) completed three successful runs of an international standard white-water course (grade 3 rapids), targeting right and left sides of the course, in a zigzag formation. Surface EMG (sEMG) outputs were generated, bilaterally, for the rectus femoris (RF), vastus lateralis, biceps femoris and gastrocnemius, expressed as a percentage of a dynamic maximal voluntary contraction (dMVC). Only RF showed significantly higher activation than any muscle on the left side of the body, and only on the left side of the course (P = .004; ETA2 = 0.56). Other results showed no significant difference between muscle activation in the right and left legs during each run, nor when assessed at either the right or left side of the course (P > .05). These findings indicate that contralateral symmetry in lower limb muscle activation is evident during white-water kayaking. This symmetry may provide a stable base to allow more asymmetrical upper body and trunk movements to be fully optimised. Lower body symmetry development should be considered useful in targeted training programmes for white-water kayakers. [ABSTRACT FROM PUBLISHER]