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Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.

For decades, artificial ground freezing (AGF) has been used as a temporary soil stabilization and waterproofing technique in multiple geotechnical engineering applications. Experience gained from AGF experiments indicates that the pore water expansion during freezing and the resulting pressure have the potential to induce ground movements in adjacent nonfrozen areas. This process was investigated in this paper using a comprehensive set of in situ temperature and displacement monitoring data collected in the Cigar Lake underground mine, Canada. The data set allowed to investigate the mechanical impact of freezing on a mine tunnel and prompted the need to derive a fully coupled thermo-hydro-mechanical model to predict ground temperature and displacements. Thermodynamically consistent, the model developed for this study is based on a macroscopic continuum approach and uses simplifying assumptions to overcome the computational difficulties associated with the modeling of complex mining environments over a long period of time. This model was used to perform three-dimensional finite-element simulations of the ground freezing and excavation activities in the Cigar Lake mine, showing good agreement with field measurements.

The aims of this study were to investigate the effects of a six-week in-season period of soccer training and games (congested period) on plasma volume variations (PV), hematological parameters, and physical fitness in elite players. In addition, we analyzed relationships between training load, hematological parameters and players' physical fitness. Eighteen elite players were evaluated before (T1) and after (T2) a six-week in-season period interspersed with 10 soccer matches. At T1 and T2, players performed the Yo-Yo intermittent recovery test level 1 (YYIR1), the repeated shuttle sprint ability test (RSSA), the countermovement jump test (CMJ), and the squat jump test (SJ). In addition, PV and hematological parameters (erythrocytes [M/mm3], hematocrit [%], hemoglobin [g/dl], mean corpuscular volume [fl], mean corpuscular hemoglobin content [pg], and mean hemoglobin concentration [%]) were assessed. Daily ratings of perceived exertion (RPE) were monitored in order to quantify the internal training load. From T1 to T2, significant performance declines were found for the YYIR1 (p<0.001, effect size [ES] = 0.5), RSSA (p<0.01, ES = 0.6) and SJ tests (p< 0.046, ES = 0.7). However, no significant changes were found for the CMJ (p = 0.86, ES = 0.1). Post-exercise, RSSA blood lactate (p<0.012, ES = 0.2) and PV (p<0.01, ES = 0.7) increased significantly from T1 to T2. A significant decrease was found from T1 to T2 for the erythrocyte value (p<0.002, ES = 0.5) and the hemoglobin concentration (p<0.018, ES = 0.8). The hematocrit percentage rate was also significantly lower (p<0.001, ES = 0.6) at T2. The mean corpuscular volume, mean corpuscular hemoglobin content and the mean hemoglobin content values were not statistically different from T1 to T2. No significant relationships were detected between training load parameters and percentage changes of hematological parameters. However, a significant relationship was observed between training load and changes in RSSA performance (r = -0.60; p<0.003). An intensive period of \"congested match play\" over 6 weeks significantly compromised players' physical fitness. These changes were not related to hematological parameters, even though significant alterations were detected for selected measures.

Background Small-sided soccer games (SSSG) are a specific exercise regime with two small teams playing against each other on a relatively small pitch. There is evidence from original research that SSSG exposure provides performance and health benefits for untrained adults. Objectives The aim of this systematic review was to summarize recent evidence on the acute and long-term effects of SSSG on physical fitness, physiological responses, and health indices in healthy untrained individuals and clinical populations. Methods This systematic literature search was conducted in four electronic databases (PubMed, Web of Science, SPORTDiscus) from inception until June 2019. The following key terms (and synonyms searched for by the MeSH database) were included and combined using the operators “AND”, “OR”, “NOT”: ((soccer OR football) AND (“soccer training” OR “football training” OR “soccer game*” OR “small-sided soccer game*”) AND (“physical fitness” OR “physiological adaptation*” OR “physiological response*” OR health OR “body weight” OR “body mass” OR “body fat” OR “bone composition” OR “blood pressure”)). The search syntax initially identified 1145 records. After screening for titles, abstracts, and full texts, 41 studies remained that examined the acute (7 studies) and long-term effects (34 studies) of SSSG-based training on physical fitness, physiological responses, and selected alth indices in healthy untrained individuals and clinical populations. Results No training-related injuries were reported in the 41 acute and long-term SSSG studies. Typically, a single session of SSSG lasted 12–20 min (e.g., 3 × 4 min with 3 min rest or 5 × 4 min with 4 min rest) involving 4–12 players (2 vs. 2 to 6 vs. 6) at an intensity ≥ 80% of HR max . Following single SSSG session, high cardiovascular and metabolic demands were observed. Specifically, based on the outcomes, the seven acute studies reported average heart rates (HR) ≥ 80% of HR max (165–175 bpm) and mean blood lactate concentrations exceeding 5 mmol/l (4.5–5.9 mmol/l) after single SSSG sessions. Based on the results of 34 studies (20 with healthy untrained, 10 with unhealthy individuals, and 4 with individuals with obesity), SSSG training lasted between 12 and 16 weeks and was performed 2–3 times per week. SSSG had positive long-term effects on physical fitness (e.g., Yo–Yo IR1 performance), physiological responses including maximal oxygen uptake (VO 2max) [+ 7 to 16%], and many health-related markers such as blood pressure (reductions in systolic [− 7.5%] and diastolic [− 10.3%] blood pressure), body composition (decreased fat mass [− 2 to − 5%]), and improved indices of bone health (bone mineral density: [+ 5 to 13%]; bone mineral content: [+ 4 to 5%]), and metabolic (LDL-cholesterol [− 15%] as well as cardiac function (left-ventricular internal diastolic diameter [+ 8%], end diastolic volume [+ 21%], left-ventricular mass index [+ 18%], and left-ventricular ejection fraction [+ 8%]). Irrespective of age or sex, these health benefits were observed in both, untrained individuals and clinical populations. Conclusions In conclusion, findings from this systematic review suggest that acute SSSG may elicit high cardiovascular and metabolic demands in untrained healthy adults and clinical populations. Moreover, this type of exercise is safe with positive long-term effects on physical fitness and health indices. Future studies are needed examining the long-term effects on physical fitness and physiological adaptations of different types of SSSG training (e.g., 3 vs. 3; 6 vs. 6) in comparison to continuous or interval training in different cohorts.

We review the effects of acute and long-term physical activity on adipokine levels in individuals with type 2 diabetes (T2D). Three electronic databases were searched. Studies made in animal models were excluded, while studies based on participants with and without T2D, and also studies with type 1 diabetes were included. Of the 2,450 citations, 63 trials, including randomised control trials, cross-sectional and longitudinal studies, met our inclusion criteria. Seventy and five percent of studies reported the effects of physical activity on tumor necrosis factor-alpha (TNFα), interleukin 6 (IL-6), adiponectin, visfatin, omentin-1, and leptin levels. There are no robust results due to variations in exercise modality, intensity, duration, and also differences in cohort characteristics in the literature. Only four studies described the effects of an acute session of physical activity on adipokine levels. Overall, physical activity improves diabetes status by regulating adipokine levels. However, long-term aerobic + resistance training combined with dietary modifications is likely to be a more effective strategy for improving adipokines profiles in patients with type 2 diabetes.

The rapid development of groundwater systems as part of urban water supplies around the globe is raising critical questions regarding the sustainable management of this essential resource. Yet, in many major cities, the absence of an effective policy regime means that the practice of groundwater exploitation is driven by the actions of domestic households and drilling contractors. Understanding what shapes the decisions and practices of these actors, their understandings of the groundwater resource and the extent to which scientific knowledge shapes this understanding, is an area of critical importance that is currently under-researched. Using a mixed-methods methodology, the paper explores domestic practices of groundwater abstraction in Lagos, Nigeria. It finds that there is a disjuncture between the households who are actively shaping exploitation of the groundwater resource on a day-to-day basis and science and state actors. This disjuncture results in household decisions that are influenced by commonly held, but potentially outdated, perceptions of the groundwater resource rather than scientific evidence or policy instruments. The unseen nature of groundwater resources effectively renders the scale of changing groundwater conditions invisible to households and the state, adding to the challenge of influencing practice. Addressing this disjuncture requires not just more scientific knowledge, but also the active construction of interfaces with, and between, non-state actors through which knowledge can be confronted, discussed and shared.

To examine the effects of two high-intensity intermittent training (HIIT) programs of varying intensities (100% vs. 110% of maximal aerobic velocity [MAV]) on metabolic, hormonal and inflammatory markers in young men. Thirty-seven active male volunteers were randomly assigned into: HIIT experimental groups (100% MAV [EG , n = 9] and 110% MAV [EG , n = 9]) and a control groups (CG , n = 9 and CG , n = 9). Particpants performed high intesity intermittent exercise test (HIIE) at 100% or 110% MAV. Venous blood samples were obtained before, at the end of HIIE and at 15 min of recovery, and before and after 8 weeks of HIIT programs. After training, Glucose was lower (p < 0.01) in EG (d = 0.72) and EG (d = 1.20) at the end of HIIE, and at 15 min recovery only in EG (d = 0.95). After training, Insulin and Cortisol were lower than before training in EG and EG at the end of HIIE (p < 0.001). After HIIT, IL-6 deceased (p < 0.001) in EG (d = 1.43) and EG (d = 1.56) at rest, at the end of HIIE (d = 1.03; d = 1.75, respectively) and at 15 min of recovery (d = 0.88;d = 1.7, respectively). This decrease was more robust (p < 0.05) in EG compared to EG . After HIIT, TNF-α deceased (p < 0.001) in EG (d = 1.43) and EG (d = 0.60) at rest, at the end of HIIE (0.71 < d < 0.98) and at 15 min of recovery (0.70 < d < 2.78). HIIT with 110% MAV is more effective in young males on the improvements of some metabolic (Glucose), hormonal (Cortisol) and inflammatory (IL-6) markers at rest, at the end of HIIE and 15 min of recovery than training at 100 % MAV.

Although shallow groundwater (<50 mbgl) sustains the vast majority of improved drinking-water supplies in rural Africa, there is little information on how resilient this resource may be to future changes in climate. This study presents results of a groundwater survey using stable isotopes, CFCs, SF 6 , and 3 H across different climatic zones (annual rainfall 400–2,000 mm/year) in West Africa. The purpose was to quantify the residence times of shallow groundwaters in sedimentary and basement aquifers, and investigate the relationship between groundwater resources and climate. Stable-isotope results indicate that most shallow groundwaters are recharged rapidly following rainfall, showing little evidence of evaporation prior to recharge. Chloride mass-balance results indicate that within the arid areas (<400 mm annual rainfall) there is recharge of up to 20 mm/year. Age tracers show that most groundwaters have mean residence times (MRTs) of 32–65 years, with comparable MRTs in the different climate zones. Similar MRTs measured in both the sedimentary and basement aquifers suggest similar hydraulic diffusivity and significant groundwater storage within the shallow basement. This suggests there is considerable resilience to short-term inter-annual variation in rainfall and recharge, and rural groundwater resources are likely to sustain diffuse, low volume abstraction.

This paper presents a new approach for salt cavern design, based on the use of the onset of dilatancy as a design threshold. In the proposed approach, a rheological model that includes dilatancy at the constitutive level is developed, and a strain-based dilatancy criterion is defined. As compared to classical design methods that consist in simulating cavern behavior through creep laws (fitted on long-term tests) and then using a criterion (derived from short-terms tests or experience) to determine the stability of the excavation, the proposed approach is consistent both with short- and long-term conditions. The new strain-based dilatancy criterion is compared to a stress-based dilatancy criterion through numerical simulations of salt caverns under cyclic loading conditions. The dilatancy zones predicted by the strain-based criterion are larger than the ones predicted by the stress-based criteria, which is conservative yet constructive for design purposes.

The sustainability of Pervious Concrete (PC) can be enhanced by the utilization of waste materials for its construction. Employment of Sorghum Husk Ash (SHA) in partially replacing binder to produce a more sustainable PC was carried out in this research. Preparation of various mixtures of PC was done adopting the same size of aggregate (4.75 - 9.50), the same water/cement ratio (0.4) as well as the same aggregate/cement ration (4:1) and was investigated at 0, 5, 10, 15, 20 and 25 % substitution levels of binder with SHA. Produced PC samples were tested for density, porosity, permeability and compressive strength. The results revealed that density decreased while permeability and porosity raised with rising percentage of SHA. Fresh density was obtained to range from 2000 to 1965 kgm−3 whereas hardened density ranged between 1981 and 1940 kgm−3, 21.5 to 24.5 % values were obtained for porosity while permeability had values of 4.8 to 10.1 mms−1 for 0 - 25 % SHA correspondingly. The compressive strengths of 8.2 Nmm−2 was achieved for 25% SHA and 11.4 Nmm−2 for 0 % at 28 days curing time. The 5% SHA was found to be 13.2 Nmm−2 which is 16 % greater than 0 % SHA PC while that of 10 - 25 % correspondingly reduced by 4.4 - 28.1 %. The research revealed that SHA can practically be utilised to substitute cement with comparable and even make a better mixture than using 100 percent cement in PC fabrication.