Cold-Water Immersion and Lower Limb Muscle Oxygen Consumption as Measured by Near-Infrared Spectroscopy in Trained Endurance Athletes.

CONTEXT: Cold-water immersion (CWI) has been reported to reduce tissue metabolism postimmersion, but physiological data are lacking regarding the muscle metabolic response to its application. Near-infrared spectroscopy (NIRS) is a noninvasive optical technique that can inform muscle hemodynamics and tissue metabolism. OBJECTIVE: To investigate the effects of CWI at 2 water temperatures (10°C and 15°C) on NIRS-calculated measurements of muscle oxygen consumption (mVO2). DESIGN: Crossover study. SETTING: University sports rehabilitation center. PATIENTS OR OTHER PARTICIPANTS: A total of 11 male National Collegiate Athletic Association Division II long-distance runners (age = 23.4 ± 3.4 years, height = 1.8 ± 0.1 m, mass = 68.8 ± 10.7 kg, mean adipose tissue thickness = 6.7 ± 2.7 mm). INTERVENTION(S): Cold-water immersion at 10°C and 15°C for 20 minutes. MAIN OUTCOME MEASURE(S): We calculated mVO2 preimmersion and postimmersion at water temperatures of 10°C and 15°C. Changes in tissue oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), total hemoglobin (tHb), hemoglobin difference (Hbdiff), and tissue saturation index (TSI %) were measured during the 20-minute immersion at both temperatures. RESULTS: We observed a decrease in mVO2 after immersion at both 10°C and 15°C (F1,9 = 27.7801, P = .001). During the 20-minute immersion at both temperatures, we noted a main effect of time for O2Hb (F3,27 = 14.227, P = .001), HHb (F3,27 = 5.749, P = .009), tHb (F3,27 = 24.786, P = .001), and Hbdiff (F3,27 = 3.894, P = .020), in which values decreased over the course of immersion. Post hoc pairwise comparisons showed that these changes occurred within the final 5 minutes of immersion for tHb and O2Hb. CONCLUSIONS: A 20-minute CWI at 10°C and 15°C led to a reduction in mVO2. This was greater after immersion at 10°C. The reduction in mVO2 suggests a decrease in muscle metabolic activity (ie, O2 use after CWI). Calculating mVO2 via the NIRS-occlusion technique may offer further insight into muscle metabolic responses beyond what is attainable from observing the NIRS primary signals.

An Evaluation of Service Provision and Novel Strength Assessment on Patient Outcomes in a UK-Based Pulmonary Rehabilitation Setting.

This study's purpose was to (i) assess the impact of a 7-week pulmonary rehabilitation (PR) programme upon patient outcomes; incremental shuttle walk test (ISWT), COPD assessment tool (CAT), Clinical COPD Questionnaire (CCQ) and the Hospital Anxiety and Depression Scale (HADS); (ii) assess the impact of COPD severity on ISWT, psychological functioning and quality of life measures following PR; (iii) assess the feasibility of incorporating individually prescribed one repetition maximum (1RM) training loads into the existing strength training programme. Patients were people with COPD enrolled onto one of three versions (locations A, B and C) of a 7-week PR programme, which consisted of group exercise sessions and a social plus education element. Two locations incorporated individually prescribed training loads. Minimal clinically important changes (MCICs) are reported for the ISWT across all locations. Statistically significant changes in both CAT and the CCQ were found, with MCIC's evident for CAT score overall and individually at location B. MCIC's were not found for the CCQ. No statistically significant or MCICs were evident for the HADS. MCIC's were present only in patients with mild to moderate severity for the ISWT. For the CAT, moderate, severe and very severe patients with COPD experienced MCIC's. MCIC's and statistically significant increases in 1RM strength were seen at both locations. These findings evidence an effective PR service. Basic strength exercise programming and assessment are feasible and should be implemented in PR services to maximise patient outcomes.

Regular Doses of Nature: The Efficacy of Green Exercise Interventions for Mental Wellbeing.

This study investigated the efficacy of medium-term Green Exercise (GE; being physically active within a natural environment) interventions for improving wellbeing, by pooling data collected at the start and end of participants' engagement with a range of GE interventions. Hypotheses were that (i) interventions would show good efficacy for improving wellbeing in the overall sample; (ii) compared to participants reporting 'average to high' wellbeing at the start of their project, participants with 'low' starting wellbeing would report greater improvements post-intervention; and (iii) improvements would significantly differ between age groups. The pooled dataset was categorized in line with UK norms (n = 318) and analyzed using a standardized meta-analysis approach. Effect size was large: g = 0.812 (95% CI [0.599, 1.025]), and differences in wellbeing changes associated with project duration, age or sex were not statistically significant. Compared to those reporting 'average-high' starting wellbeing, participants reporting 'low' starting wellbeing exhibited greater improvements (BCa 95% CI [-31.8, -26.5]), with 60.8% moving into the 'average-high' wellbeing category. GE can play an important role in facilitating wellbeing and can provide alternative pathways for health and social care practice. Public health commissioners should consider integrating such interventions for patients experiencing low wellbeing or associated comorbidities.

Affective Outcomes of Group versus Lone Green Exercise Participation.

'Green exercise' (being physically active within a natural environment) research has examined the influence of environmental setting on health and wellbeing-related exercise outcomes. However, it is not known whether social exercise settings influence green exercise-associated changes in mood, self-esteem, and connection to nature. This study directly compared outcomes of participating in green exercise alone compared to in a group. Using repeated measures, counterbalanced and randomized-crossover design, participants (n = 40) completed two 3 km runs around sports fields. These fields had a relatively flat grass terrain, predominant view of trees, and open grassland. On one occasion participants ran alone and on the other they ran in a group of 4-5 participants. Questionnaire measures of mood, self-esteem, and connection to nature were completed immediately pre- and post-run. Across all of the measures, two-way mixed ANOVAs found that there were statistically significant effects for time but not for time-by-condition interactions. The simplest interpretation of this finding is that social setting does not influence individuals' attainment of the psychological outcomes of green exercise participation. However, we discuss the possibility that more complex processes might underpin this finding.

Constructed wetlands for steel slag leachate management: Partitioning of arsenic, chromium, and vanadium in waters, sediments, and plants.

Constructed wetlands can treat highly alkaline leachate resulting from the weathering of steel slag before reuse (e.g. as aggregate) or during disposal in repositories and legacy sites. This study aimed to assess how metal(loid)s soluble at high pH, such as arsenic (As), chromium (Cr), and vanadium (V) are removed in constructed wetlands and how they accumulate in the sediments and the plants (Phragmites australis, common reed). The results show that reedbeds were very effective at removing calcium (98%), aluminium (81%), barium (98%), chromium (90%), gallium (80%), nickel (98%), and zinc (98%), and lowering pH and alkalinity. No statistical difference was found for As and V between leachate influent and wetland samples, showing that these metal(loid)s were not efficiently removed. As, Cr, and V were significantly higher in the reedbed sediments than in a reference site. However, sediment concentrations are not at levels that would pose a concern regarding reuse for agricultural purposes (average values of 39 ±â€¯26 mg kg-1 for As, 108 ±â€¯15 mg kg-1 for Cr, and 231 ±â€¯34 mg kg-1 for V). Also, there is no significant uptake of metals by the aboveground portions of the reeds compared to reference conditions. Results show statistically significant enrichment in metal(loid)s in rhizomes and also a seasonal effect on the Cr concentrations. The data suggest minimal risk of oxyanion-forming element uptake and cycling in wetlands receiving alkaline steel slag.

Mediterranean isolation preconditioning the Earth System for late Miocene climate cooling.

A global Neogene cooling trend culminated ~7 million years ago with the onset of Greenland glaciation. Increased ocean-atmosphere interaction and low- to high-latitude circulation are thought to be key factors in reorganizing late Miocene global temperature and precipitation patterns, but the drivers of this reorganization have yet to be identified. Here, we present new information about the evolution of the Atlantic-Mediterranean gateway that generated Mediterranean overflow. We use sedimentary and palaeogeographic evidence to constrain the timing and dimensions of this gateway and document the initiation of a saline plume of water within the North Atlantic. Today, this saline jet entrains and transports Eastern North Atlantic water and its dissolved inorganic carbon into the interior of the ocean, contributing to the drawdown of CO2 and the sensitivity of the ocean to atmospheric changes. We show that during the Miocene this transport emerged simultaneously with gateway restriction and propose that the resulting interaction of ocean-surface and ocean-interior carbon inventories would have greatly enhanced ocean-atmosphere exchange, preconditioning the Earth System for late Miocene cooling.

Leaching behaviour of co-disposed steel making wastes: Effects of aeration on leachate chemistry and vanadium mobilisation.

Steelmaking wastes stored in landfill, such as slag and spent refractory liners, are often enriched in toxic trace metals (including V). These may become mobile in highly alkaline leachate generated during weathering. Fresh steelmaking waste was characterised using XRD, XRF, and SEM-EDX. Batch leaching tests were performed under aerated, air-excluded and acidified conditions to determine the impact of atmospheric CO2 and acid addition on leachate chemistry. Phases commonly associated with slag including dicalcium silicate, dicalcium aluminoferrite, a wüstite-like solid solution and free lime were identified, as well as a second group of phases including periclase, corundum and graphite which are representative of refractory liners. During air-excluded leaching, dissolution of free lime and dicalcium silicate results in a high pH, high Ca leachate in which the V concentration is low due to the constraint imposed by Ca3(VO4)2 solubility limits. Under aerated conditions, carbonation lowers the leachate pH and provides a sink for aqueous Ca, allowing higher concentrations of V to accumulate. Below pH 10, leachate is dominated by periclase dissolution and secondary phases including monohydrocalcite and dolomite are precipitated. Storage of waste under saturated conditions that exclude atmospheric CO2 would therefore provide the optimal environment to minimise V leaching during weathering.

Can Simulated Green Exercise Improve Recovery From Acute Mental Stress?

This exploratory study enhances previous research into green exercise and addresses a gap in the research by exploring the contribution of individual and combined senses in the recovery of mood and stress after a psychological stressor, whilst rigorously controlling exercise intensity. The hypotheses were: (i) recovery of mood and stress from a state of psychological stress would be greater following simulated green exercise compared to rest, (ii) green exercise would facilitate better recovery than exercise alone, (iii) these effects would remain 10 min following intervention, and (iv) visual stimuli alone would enhance recovery from a state of psychological stress compared to sound. Fifty participants were randomly assigned to one of five groups: REST, exercise, exercise with nature sounds, exercise with nature visual and exercise with nature sound and visual. An initial visit to obtain predicted peak power output values and to familiarize participants with the equipment being used was followed by a second visit, where participants experienced one test condition. Baseline measures of heart rate, blood pressure, total mood disturbance (TMD), and perceived stress were taken, before participants completed a stressor based on the Trier Social Stress test. Measures of heart rate and blood pressure were recorded in the last 30 s of the stressor to assess efficacy of the stressor. Immediately post stressor, measures of mood and perceived stress were taken followed by the intervention assigned (one of five described above). Measures of mood and perceived stress were taken again immediately post intervention and 10 min post intervention. Results showed that green exercise improved mood and stress scores more than exercise alone or REST. For both TMD and perceived stress, improvements in all simulated nature conditions were significantly improved compared to REST or exercise alone immediately post intervention. There were no significant changes 10 min post intervention in either mood or perceived stress compared to immediately post intervention values in any of the groups. This study suggests that environmental exercise settings including nature sounds, visual or both combined should be considered as important in the use of exercise as a therapeutic activity or recovery from acute psychological stress.

A microbial role in the construction of Mono Lake carbonate chimneys?

Lacustrine carbonate chimneys are striking, metre-scale constructions. If these were bioinfluenced constructions, they could be priority targets in the search for early and extraterrestrial microbial life. However, there are questions over whether such chimneys are built on a geobiological framework or are solely abiotic geomorphological features produced by mixing of lake and spring waters. Here, we use correlative microscopy to show that microbes were living around Pleistocene Mono Lake carbonate chimneys during their growth. A plausible interpretation, in line with some recent works by others on other lacustrine carbonates, is that benthic cyanobacteria and their associated extracellular organic material (EOM) formed tubular biofilms around rising sublacustrine spring vent waters, binding calcium ions and trapping and binding detrital silicate sediment. Decay of these biofilms would locally have increased calcium and carbonate ion activity, inducing calcite precipitation on and around the biofilms. Early manganese carbonate mineralisation was directly associated with cell walls, potentially related to microbial activity though the precise mechanism remains to be elucidated. Much of the calcite crystal growth was likely abiotic, and no strong evidence for either authigenic silicate growth or a clay mineral precursor framework was observed. Nevertheless, it seems likely that the biofilms provided initial sites for calcite nucleation and encouraged the primary organised crystal growth. We suggest that the nano-, micro- and macroscale fabrics of these Pleistocene Mono Lake chimneys were affected by the presence of centimetre-thick tubular and vertically stacked calcifying microbial mats. Such carbonate chimneys represent a promising macroscale target in the exploration for ancient or extraterrestrial life.

Recovery of Al, Cr and V from steel slag by bioleaching: Batch and column experiments.

Steel slag is a major by-product of the steel industry and a potential resource of technology critical elements. For this study, a basic oxygen furnace (BOF) steel slag was tested for bacterial leaching and recovery of aluminium (Al), chromium (Cr), and vanadium (V). Mixed acidophilic bacteria were adapted to the steel slag up to 5% (w/v). In the batch tests, Al, Cr, and V were bioleached significantly more from steel slag than in control treatments. No statistical difference was observed arising from the duration of the leaching (3 vs 6 d) in the batch tests. Al and Cr concentrations in the leachate were higher for the smaller particle size of the steel slag (<75 µm), but no difference was observed for V. In the column tests, no statistical difference was found for pH, Al, Cr and V between the live culture (one-step bioleaching) and the supernatant (two-step bioleaching). The results show that the culture supernatant can be effectively used in an upscaled industrial application for metal recovery. If bioleaching is used in the 170-250 million tonnes of steel slag produced per year globally, significant recoveries of metals (100% of Al, 84% of Cr and 8% of V) can be achieved, depending on the slag composition. The removal and recovery percentages of metals from the leachate with Amberlite®IRA-400 are relatively modest (<67% and <5%, respectively), due to the high concentration of competing ions (SO42-, PO43-) in the culture medium. Other ion exchange resins can be better suited for the leachate or methods such as selective precipitation could improve the performance of the resin. Further research is needed to minimise interference and maximise metal recovery.

Hydration of dicalcium silicate and diffusion through neo-formed calcium-silicate-hydrates at weathered surfaces control the long-term leaching behaviour of basic oxygen furnace (BOF) steelmaking slag.

Alkalinity generation and toxic trace metal (such as vanadium) leaching from basic oxygen furnace (BOF) steel slag particles must be properly understood and managed by pre-conditioning if beneficial reuse of slag is to be maximised. Water leaching under aerated conditions was investigated using fresh BOF slag at three different particle sizes (0.5-1.0, 2-5 and 10 × 10 × 20 mm blocks) and a 6-month pre-weathered block. There were several distinct leaching stages observed over time associated with different phases controlling the solution chemistry: (1) free-lime (CaO) dissolution (days 0-2); (2) dicalcium silicate (Ca2SiO4) dissolution (days 2-14) and (3) Ca-Si-H and CaCO3 formation and subsequent dissolution (days 14-73). Experiments with the smallest size fraction resulted in the highest Ca, Si and V concentrations, highlighting the role of surface area in controlling initial leaching. After ~2 weeks, the solution Ca/Si ratio (0.7-0.9) evolved to equal those found within a Ca-Si-H phase that replaced dicalcium silicate and free-lime phases in a 30- to 150-µm altered surface region. V release was a two-stage process; initially, V was released by dicalcium silicate dissolution, but V also isomorphically substituted for Si into the neo-formed Ca-Si-H in the alteration zone. Therefore, on longer timescales, the release of V to solution was primarily controlled by considerably slower Ca-Si-H dissolution rates, which decreased the rate of V release by an order of magnitude. Overall, the results indicate that the BOF slag leaching mechanism evolves from a situation initially dominated by rapid hydration and dissolution of primary dicalcium silicate/free-lime phases, to a slow diffusion limited process controlled by the solubility of secondary Ca-Si-H and CaCO3 phases that replace and cover more reactive primary slag phases at particle surfaces.

The importance of greenspace for mental health.

There is an urgent global need for accessible and cost-effective pro-mental health infrastructure. Public green spaces were officially designated in the 19th century, informed by a belief that they might provide health benefits. We outline modern research evidence that greenspace can play a pivotal role in population-level mental health.

Green Mind Theory: How Brain-Body-Behaviour Links into Natural and Social Environments for Healthy Habits.

We propose a Green Mind Theory (GMT) to link the human mind with the brain and body, and connect the body into natural and social environments. The processes are reciprocal: environments shape bodies, brains, and minds; minds change body behaviours that shape the external environment. GMT offers routes to improved individual well-being whilst building towards greener economies. It builds upon research on green exercise and nature-based therapies, and draws on understanding derived from neuroscience and brain plasticity, spiritual and wisdom traditions, the lifeways of original cultures, and material consumption behaviours. We set out a simple metaphor for brain function: a bottom brain stem that is fast-acting, involuntary, impulsive, and the driver of fight and flight behaviours; a top brain cortex that is slower, voluntary, the centre for learning, and the driver of rest and digest. The bottom brain reacts before thought and directs the sympathetic nervous system. The top brain is calming, directing the parasympathetic nervous system. Here, we call the top brain blue and the bottom brain red; too much red brain is bad for health. In modern high-consumption economies, life has often come to be lived on red alert. An over-active red mode impacts the gastrointestinal, immune, cardiovascular, and endocrine systems. We develop our knowledge of nature-based interventions, and suggest a framework for the blue brain-red brain-green mind. We show how activities involving immersive-attention quieten internal chatter, how habits affect behaviours across the lifecourse, how long habits take to be formed and hard-wired into daily practice, the role of place making, and finally how green minds could foster prosocial and greener economies. We conclude with observations on twelve research priorities and health interventions, and ten calls to action.

Hydraulic and biotic impacts on neutralisation of high-pH waters.

The management of alkaline (pH11-12.5) leachate is an important issue associated with the conditioning, afteruse or disposal of steel slags. Passive in-gassing of atmospheric CO2 is a low cost option for reducing Ca(OH)2 alkalinity, as Ca(OH)2 is neutralised by carbonic acid to produce CaCO3. The relative effectiveness of such treatment can be affected by both the system geometry (i.e. stepped cascades versus settlement ponds) and biological colonization. Sterilized mesocosm experiments run over periods of 20days showed that, due to more water mixing and enhanced CO2 dissolution at the weirs, the cascade systems (pH11.2→9.6) are more effective than settlement ponds (pH11.2→11.0) for lowering leachate alkalinity in all the tested conditions. The presence of an active microbial biofilm resulted in significantly more pH reduction in ponds (pH11.2→9.5), but had a small impact on the cascade systems (pH11.2→9.4). The pH variation in biofilm colonized systems shows a diurnal cycle of 1 to 1.5pH units due to CO2 uptake and release associated with respiration and photosynthesis. The results demonstrate that, where gradient permits, aeration via stepped cascades are the best option for neutralisation of steel slag leachates, and where feasible, the development of biofilm communities can also help reduce alkalinity.

Removal and recovery of vanadium from alkaline steel slag leachates with anion exchange resins.

Leachable vanadium (V) from steel production residues poses a potential environmental hazard due to its mobility and toxicity under the highly alkaline pH conditions that characterise these leachates. This work aims to test the efficiency of anion exchange resins for vanadium removal and recovery from steel slag leachates at a representative average pH of 11.5. Kinetic studies were performed to understand the vanadium sorption process. The sorption kinetics were consistent with a pseudo-first order kinetic model. The isotherm data cannot differentiate between the Langmuir and Freundlich models. The maximum adsorption capacity (Langmuir value qmax) was 27 mg V g-1 resin. In column anion exchange, breakthrough was only 14% of the influent concentration after passing 90 L of steel slag leachate with 2 mg L-1 V through the column. When eluting the column 57-72% of vanadium was recovered from the resin with 2 M NaOH. Trials on the reuse of the anion exchange resin showed it could be reused 20 times without loss of efficacy, and on average 69% of V was recovered during regeneration. The results document for the first time the use of anion exchange resins to remove vanadium from steel slag leachate. As an environmental contaminant, removal of V from leachates may be an obligation for long-term management requirements of steel slag repositories. Vanadium removal coupled with the recovery can potentially be used to offset long-term legacy treatment costs.

Timing and causes of North African wet phases during the last glacial period and implications for modern human migration.

We present the first speleothem-derived central North Africa rainfall record for the last glacial period. The record reveals three main wet periods at 65-61 ka, 52.5-50.5 ka and 37.5-33 ka that lead obliquity maxima and precession minima. We find additional minor wet episodes that are synchronous with Greenland interstadials. Our results demonstrate that sub-tropical hydrology is forced by both orbital cyclicity and North Atlantic moisture sources. The record shows that after the end of a Saharan wet phase around 70 ka ago, North Africa continued to intermittently receive substantially more rainfall than today, resulting in favourable environmental conditions for modern human expansion. The encounter and subsequent mixture of Neanderthals and modern humans - which, on genetic evidence, is considered to have occurred between 60 and 50 ka - occurred synchronously with the wet phase between 52.5 and 50.5 ka. Based on genetic evidence the dispersal of modern humans into Eurasia started less than 55 ka ago. This may have been initiated by dry conditions that prevailed in North Africa after 50.5 ka. The timing of a migration reversal of modern humans from Eurasia into North Africa is suggested to be coincident with the wet period between 37.5 and 33 ka.

Vanadium removal and recovery from bauxite residue leachates by ion exchange.

Bauxite residue is an important by-product of the alumina industry, and current management practices do not allow their full valorisation, especially with regard to the recovery of critical metals. This work aims to test the efficiency of ion exchange resins for vanadium (V) removal and recovery from bauxite residue leachates at alkaline pH (11.5 and 13). As an environmental pollutant, removal of V from leachates may be an obligation of bauxite residue disposal areas (BRDA) long-term management requirements. Vanadium removal from the leachate can be coupled with the recovery, and potentially can be used to offset long-term legacy treatment costs in legacy sites. Kinetics studies were performed to understand the adsorption process. The rate kinetics for the V adsorption was consistent with the pseudo-first-order kinetic model, with a higher adsorption rate for pH 11.5 (1.2 min-1). Adsorption isotherm data fitted better to Freundlich equations than to the Langmuir model. The maximum adsorption capacity (Langmuir value q max) was greatest for pH 13 (9.8 mg V g-1 resin). In column tests, breakthrough was reached at 70 bed volumes with the red mud leachate at pH 13, while no breakthrough was achieved with the effluent at pH 11.5. In regeneration, 42 and 76 % of V were eluted from the resin with 2 M NaOH from the red mud leachate at pH 13 and 11.5, respectively. Further optimization will be needed to upscale the treatment.

Influences of Green Outdoors versus Indoors Environmental Settings on Psychological and Social Outcomes of Controlled Exercise.

This study addressed a methodological gap by comparing psychological and social outcomes of exercise in green outdoors versus built indoors settings, whilst rigorously controlling exercise mode and intensity. The hypotheses were that greater improvements or more desirable values for directed attention, mood, perceived exertion, social interaction time, intention for future exercise behaviour and enjoyment would be associated with outdoors compared to indoors exercise. Following a baseline session, paired participants completed two conditions of 15 min of cycling on an ergometer placed outside in a natural environment and inside in a laboratory setting in a randomized, counter-balanced order. At pre- and post-exercise, directed attention was measured with the digit span backwards task, and mood was assessed with the Profile of Mood States. During the exercise session, visual and verbal interactions were recorded by means of experimenter observations. After each exercise session, participants provided self-reports of their enjoyment of the exercise, perceived exertion and intention for future exercise in the same environment. Social interaction time was significantly greater during outdoors exercise versus indoors; on average, participants engaged in three minutes more social interaction during exercise outdoors compared to indoors. Social interaction time significantly predicted intention for future exercise in the outdoors condition, but did not in the indoor condition. There was a significant time by condition interaction for directed attention. Scores worsened in the indoors condition, but improved in the outdoors condition. There was no statistically-significant time by condition interaction for mood and no significant difference between conditions for either perceived exertion or intention. Taken together, these findings show that exercise in a natural environment may promote directed attention and social interactions, which may positively influence future exercise intentions.