Daily Cycling Research Articles

Safety and Feasibility of Early Activity-Based Therapy Following Severe Traumatic Spinal Cord Injury: Results from a Single-Arm Pilot Trial.

Early activity-based therapy (E-ABT) has the potential to decrease complications and radically improve neurofunctional recovery following traumatic spinal cord injury (TSCI). Unfortunately, E-ABT after TSCI has never been attempted in humans due to practical obstacles and potential safety concerns. This study aims to report on the safety and feasibility outcomes of the Protocol for Rapid Onset of Mobilization in Patients with Traumatic SCI (PROMPT-SCI) trial: the first-ever trial of E-ABT in critically ill patients who suffered a severe TSCI. To do so, 45 patients with severe TSCI were recruited to participate in the PROMPT-SCI trial between April 2021 and August 2023. The intervention consisted of daily 30-min sessions of motor-assisted in-bed leg cycling for 14 days, starting within 48 h of early surgery (≈72 h from the initial trauma). Adverse events were closely monitored, and completion rates were evaluated. Out of the 45 participants, 36 (80%) completed a full and safe session within 48 h of surgery and all participants managed to achieve this outcome within 72 h of surgery. Over the full 14-day protocol, the average completion rate of sessions was 87.2 ± 22.7% (range: 7.1-100.0%). A total of three patients were mechanically ventilated during the protocol and all three had 100% completion of sessions. Frequent reasons for unattempted/incomplete sessions were scheduling conflicts with activities related to care (e.g., bronchoscopy) and fatigue/uncontrolled pain before initiating cycling. We also report no neurological deterioration caused by cycling and no major adverse event recorded during or between sessions. In conclusion, this study suggests that E-ABT can be safely initiated within 48-72 h after a severe TSCI with no major adverse event. In the form of daily passive in-bed leg cycling, E-ABT is also acceptable for target users, and feasible over the course of the first weeks after the initial trauma, as shown by our excellent rate of completed sessions (87%). The present results also suggest that improved collaboration with intensive care unit staff, including intensivists and nurses, could improve these rates even further.

Impact of Daily Lower-Body Negative Pressure or Cycling Followed by Venous Constrictive Thigh Cuffs on Bedrest-Induced Orthostatic Intolerance.

Orthostatic intolerance occurs following immobilization in patients on Earth and in astronauts after spaceflight. Head-down tilt bedrest is a terrestrial model for weightlessness and induces orthostatic intolerance. We hypothesized that lower-body negative pressure (LBNP) or cycling followed by wearing venous constrictive thigh cuffs mitigates orthostatic intolerance after head-down tilt bedrest. We enrolled 47 healthy individuals (20 women, 35±9 years) to a 30-day strict head-down tilt bedrest study. During bedrest, they were assigned to 6 hours of 25 mm Hg LBNP (n=12) per day and 1 hour of supine cycling followed by 6 hours of venous constriction through thigh cuffs 6 days per week (n=12), 6 hours of daily upright sitting (positive control, n=11), or no countermeasure (negative control, n=12). We measured orthostatic tolerance as the time to presyncope during 80° head-up tilt testing with incremental LBNP before and immediately after bedrest. We determined plasma volume with carbon monoxide rebreathing before and at the end of bedrest. After bedrest, orthostatic tolerance decreased 540±457 seconds in the control group, 539±68 seconds in the cycling group, 217±379 seconds in the LBNP group, and 289±89 seconds in the seated group (P<0.0001 time point, P=0.009 for group differences). Supine and upright heart rate increased in all groups following bedrest. Plasma volume was only maintained in the cycling group but decreased in all others (interaction countermeasure×time point P<0.0001). Six hours of moderate LBNP training was as effective as sitting in attenuating orthostatic intolerance after 30 days of head-down tilt bedrest. Daily cycling exercise followed by 6 hours of wearing venous constrictive thigh cuffs, while maintaining plasma volume, did not improve orthostatic tolerance. URL: https://www.bfarm.de/EN; Identifiers: DRKS00027643 and DRKS00030848.

Diurnal humidity cycle driven selective ion transport across clustered polycation membrane

The ability to manipulate the flux of ions across membranes is a key aspect of diverse sectors including water desalination, blood ion monitoring, purification, electrochemical energy conversion and storage. Here we illustrate the potential of using daily changes in environmental humidity as a continuous driving force for generating selective ion flux. Specifically, self-assembled membranes featuring channels composed of polycation clusters are sandwiched between two layers of ionic liquids. One ionic liquid layer is kept isolated from the ambient air, whereas the other is exposed directly to the environment. When in contact with ambient air, the device showcases its capacity to spontaneously produce ion current, with promising power density. This result stems from the moisture content difference of ionic liquid layers across the membrane caused by the ongoing process of moisture absorption/desorption, which instigates selective transmembrane ion flux. Cation flux across the polycation clusters is greatly inhibited because of intensified charge repulsion. However, anions transport across polycation clusters is amplified. Our research underscores the potential of daily cycling humidity as a reliable energy source to trigger ion current and convert it into electrical current.

Short‐Term Arsenic Cycling in a Shallow, Polymictic Lake

AbstractArsenic (As), a harmful contaminant present in many urban lakes, can negatively impact lake ecosystem health when aqueous concentrations are elevated. We observed repeated diel oscillations in As concentrations in the bottom waters of a shallow, temperate lake during a weeklong period. In this work, we explore four mechanistic hypotheses to explain the diel As cycles based on the physical and biogeochemical processes that were investigated during the study. Despite pH being known to control diel As cycles in rivers, we determined that this mechanism was inconsistent with As dynamics observed in Lake Killarney. Instead, we found that iron and manganese concentrations oscillated simultaneously with As concentrations and that redox conditions adjacent to the lakebed likely controlled the near‐bed availability of these three elements. However, based on timescale analysis, we determined that biogeochemical processes at the sediment water interface alone could not have led to the daily oscillations in bottom water concentrations. Rather, turbulence from convective mixing was necessary to transport dissolved species. Notably, we saw that the timing and intensity of peaks in convectively driven turbulence were consistent with observed diel fluctuations in bottom water As. Our results indicate that physical mixing is key in controlling As transport and concentrations on diel timescales within shallow lakes. Understanding the daily cycling of As in shallow lakes is essential for predicting the degree to which lake biota are exposed to this contaminant. Diel oscillations in As concentrations should be considered when designing sampling methods to assess the water quality of contaminated sites.

The energy management strategy of a loop microgrid with wind energy prediction and energy storage system day-ahead optimization

Microgrid has been extensively applied in the modern power system as a supplementary mode for the distributed energy resources. The microgrid with wind energy is usually vulnerable to the intermittence and uncertainty of the wind energy. To increase the robustness of the microgrid, the energy storage system (ESS) is necessary to compensate the power imbalance between the power supply and the load. To further maximize the economic efficiency of the system, the system level control for the microgrid is desired to be optimized when it is integrated with the utility grid. Aiming at the aforementioned problem, this paper comprehensively analyzes the power flow of a typical loop microgrid. A transformer-based wind power prediction (WPP) algorithm is proposed and compared with recurrent neural networks algorithm. With the historical weather data, it can accurately predict the 24 h average wind energy. Based on the predicted wind energy and the time-of-use (TOU) electricity price, a day-ahead daily cycling profile of the ESS with particle swarm optimization algorithm is introduced. It comprehensively considers the system capacity constraints and the battery degree of health. The functionality of the proposed energy management strategy is validated from three levels. First, WPP is conducted with the proposed algorithm and the true historical weather data. It has validated the accuracy of the transformer algorithm in prediction of the hourly level wind energy. Second, with the predicted wind energy, a case study is given to validate the day-ahead daily cycling profile. A typical 1 MVA microgrid is utilized as the simulation model to validate performance of the daily cycling optimization algorithm. The case study results show that the ESS daily cycling can effectively reduce the daily energy expense and help to shave the peak power demand in the grid.

Temperature Response of Double-Layer Steel Truss Bridge Girders

Double-layer steel truss continuous girders are prone to significant temperature stress, deviation, torsion, and warping, thus causing adverse temperature structural responses, and also affecting the safety and durability of bridge structures. This paper presents an investigation on time-dependent characteristics in the temperature field and temperature response of double-layer steel truss continuous bridge girders, fully considering the shielding effect subjected to different solar radiation angles during the high-temperature season. The time-dependent thermal boundary conditions and support conditions provided for the steel truss bridge structure were determined. Subsequently, a thermal analysis model for the entire structure of double-layer steel truss continuous girders was established to attain the temperature distribution law. The research results show that significant differences occur in the position and temperature difference of temperature gradients exhibited in the vertical, horizontal, and longitudinal directions in the double-layer steel truss bridge structure. The temperature distribution pattern within the chord section is mainly influenced by the environmental temperature and solar radiation intensity, along with the heat exchange between different panels. Thereafter, a validated temperature gradient formula for the component section has been proposed. The time-dependent laws in structural displacement, stress, and rotation angle under daily temperature cycling conditions have been revealed, thereby providing a theoretical basis for the life cycle construction and safety maintenance of double-layer steel truss structure bridges.

Evaluating the impact of low traffic neighbourhoods in areas with low car ownership: A natural experimental evaluation

BackgroundImproving the environment, including the streetscape, can enable walking and cycling, which impacts health. The aim of this study was to measure the impact of modal filters implemented as part of Low Traffic Neighbourhoods (LTNs) in Southwark, a borough with low car ownership located in Inner London, on driving, walking, and cycling levels. MethodologyThree neighbourhoods (Brunswick Park, North Peckham, East Faraday) introduced modal filters which restricted motorised traffic through-movement but not walking and cycling. Intervention areas were matched to control neighbourhoods with no street changes. Daily traffic, walking, and cycling counts and traffic speeds were collected using automatic counters and video monitors in all neighbourhoods at baseline and one year. In each neighbourhood we delineated ‘project’ and ‘boundary’ streets to capture potential displacement of traffic. We used a difference-in-differences analysis to estimate the effects of the LTNs by calculating the change in travel behaviours in intervention areas relative to control areas. ResultsDaily traffic counts decreased on ‘project’ streets in the intervention areas relative to controls by 860 (95% CI 409, 1312) in Brunswick Park, representing a 56% decrease (IRR 0.44, 95% CI 0.28, 0.68), and by 937 counts (95% CI 328, 1546), representing a 61% decrease (IRR 0.39, 95% CI 0.26, 0.71) in North Peckham. Traffic volumes did not significantly change in East Faraday. Across all three intervention project areas, traffic speeds decreased. Traffic levels remained unchanged on ‘boundary’ streets, with the exception of Brunswick Park, where there was an uplift in traffic levels during weekdays and peak hours. In general, there were no significant changes in daily walking and cycling counts. DiscussionFindings from this study demonstrate that modal filters can reduce traffic speeds and volumes on ‘project’ streets. Although these measures can offer a safer, less polluted, and more inviting environment for pedestrians and cyclists, areas with low car ownership may need further initiatives to boost walking and cycling.

Using Machine Learning to Improve Physical Activity: A Systematic Review

Abstract Background Many diseases that threaten public health can be prevented with policies to improve physical activity. To improve physical activity, the implementation of individual interventions at the societal level remains limited. At this point, technological devices as mobile phones, which provide access to all individuals, enable widespread implementation of public health interventions and the cost-effective use of resources. In recent years, Machine Learning has been used in various areas of health promotion, including improving physical activity. This systematic review was conducted to examine the effect of machine learning on health outcomes related to physical activity. Methods Studies on this topic from 2013 to 2023 have been accessed by five database searches. The methodological quality of the studies was assessed using the Critical Appraisal Checklists for experimental and quasi-experimental studies, developed by the Joanna Briggs Institute. This study was conducted by following the Preferred Reporting System for Systematic Reviews and Meta-Analyses. Results This systematic review included thirteen studies with a total sample size of 2945 individual. In the study, it was found that using machine learning algorithms can help to detect physical actvivity level and intensity, increase the daily step count, predict adherence to the physical activity goal, develop physical activity skills, increase the duration of daily cycling time, accessing accurate and real-time data on physical activity, personalize physical activity recommendations and identify the types of gaits. Conclusions Machine learning can be used to improve physical activity by providing more personalized and effective recommendations, using real-time feedback, and gamifying physical activity to increase motivation and adherence. Machine learning holds promise in the field of health promotion and has the potential to improve physical activity for individuals and communities. Key messages • Machine learning approaches are effective methods in determining and improving the level of physical activity on a public scale. • In terms of public health initiatives, using machine learning to improve physical activity is a cost-effective and efficient approach.

Effect of hypoxia duration and pattern on channel Catfish (Ictalurus punctatus) neuropeptide gene expression and hematology.

Commercial aquaculture production of channel catfish (Ictalurus punctatus) occurs in shallow ponds with daily cycling of dissolved oxygen concentration ranging from supersaturation to severe hypoxia. Once daily minimum dissolved oxygen concentration falls below 3.0mg O2/L, channel catfish have a reduced appetite, leading to reduced growth rates. In other fishes, upregulation of the neuropeptides corticotropin-releasing factor (CRF) and urotensin I (UI) have been implicated as initiating the mechanism responsible for decreasing appetite once an environmental stressor is detected. Channel catfish maintained at 27°C in aquaria were subjected to varying durations and patterns of hypoxia (1.75 ± 0.07mg O2/L) to evaluate underlying physiological responses to hypoxia and determine if hypothalamic CRF and UI are responsible for hypoxia-induced anorexia in channel catfish. During a short exposure to hypoxia (12h), venous PO2 was significantly lower within 6h and was coupled with an increase of hematocrit and decrease of blood osmolality, yet all responses reversed within 12h after returning to normoxia. When this pattern of hypoxia and normoxia was repeated cyclically for 5days, these physiological responses repeated daily. Extended periods of hypoxia (5days) resulted in similar hematological responses, which did not recover to baseline values during the hypoxia exposure. This study did not find a significant change in hypothalamic transcription of CRF and UI during hypoxia challenges but did identify multiple physiological adaptive responses that work together to reduce the severity of experimentally induced hypoxia in channel catfish.

Asymptotic numerical method for cyclic elasto-plasticity and its application to a steam turbine rotor

Flexible operation of the conventional power plants is necessary for the integration of renewables in the energy mix. Steam turbine rotors are one of the most affected components due to the daily thermal load cycling requirements. In order to accurately study the effect of cycling on fatigue, it is necessary to solve cyclic 3D elasto-plasticity problems for a large number of cycles. The established methods are iterative in nature to arrive at the current yield surface for each elasto-plastic step and are computationally extensive. In this paper, we propose the non-iterative Asymptotic Numerical Method (ANM) based solution technique for 3D cyclic elasto-plasticity problems for the first time by a novel regularized Kuhn-Tucker condition. Regularization techniques used in previous works take care of the partial cycle only, i.e., elastic loading, elastic-plastic transition, elasto-plastic flow and elastic unloading for simple linear work hardening models of plasticity. In the present work, the proposed method extends the applicability of ANM by incorporating elastic-plastic transition and elasto-plasticity in reverse loading, second unloading and repeated loading for any number of cycles so that the computationally efficient fatigue analysis can be carried out. In addition, the extension also includes the application of ANM to non-linear kinematic hardening through the Chaboche plasticity model combined with isotropic hardening. For these advancements, additional regularizations are proposed and implemented in a Finite Element Code. The obtained results are then compared to the solutions obtained from the conventional Newton Raphson (NR) solution technique. The proposed ANM is applied to a steam turbine rotor undergoing a typical thermal load cycling and the cyclic elasto-plastic response is compared with that obtained using the conventional Newton Raphson solution technique.

Degradation Behavior of MK35x Stacks with Chromium-Based Interconnects in Steam Electrolysis Operation

The currently ongoing commercialization of high-temperature solid oxide electrolysis (SOEL) requires the understanding of the underlying dominant degradation mechanisms to enable continuous progress in reducing stack degradation rates.In the present study, the degradation behavior of stacks with chromium-based interconnects (MK35x) and electrolyte-supported cells (ESC) developed at Fraunhofer IKTS is investigated. For this purpose, the initial electrochemical performance of 10-layer stacks was extensively characterized in various operating conditions in both fuel cell and electrolysis mode by electrochemical impedance spectroscopy (EIS). Degradation was evaluated during galvanostatic steady-state steam electrolysis operation over >3000 h in the temperature range of 800-825°C at a current density of -0.6 A cm-2, corresponding to a steam conversion rate of 75%. EIS analysis was used to separate the different loss contributions in the stack and showed that the ohmic resistance increase was the dominating performance degradation phenomenon. Moreover, electrochemical degradation rates in steady-state SOEL mode are compared to the ones in reversible mode with a daily cycling between electrolysis and fuel cell operation.Post-mortem analysis was carried out with scanning electron microscopy (SEM) to correlate the observed degradation phenomena with microstructural and morphological changes. The observed low degradation rates demonstrate that MK35x are ready for scale-up, and the present work gives guidance for operation strategies and stack design to extend their lifetime even further.

Using Triathlon Camp to Develop Youth Life Skills among Diverse Campers

Innovative recreation services, such as non-traditional camps, can help provide diverse youth a chance to engage in physical activity, develop healthy relational skills, and meet others. Twenty-two participants took part in a new, 1-week triathlon camp held on a Mid-Atlantic University campus. Participants were recruited through local parks and recreation agencies and local youth running clubs. Scholarships were given to participants who expressed financial challenges through a USA Triathlon Youth Grant. The 1-week day camp took place on a college campus. The camp served the surrounding neighborhoods, which was accurately represented in the camper demographic (i.e., half the campers were youth of color). During the week, the campers swam, biked, ran, rock climbed, and participated in other multi-sport activities to help develop proper form and skills for triathlon. As guided by the USAT Splash, Spin, Sprint Camp manual, campers participated in daily swimming, cycling, running, and other related exercises. In addition, the camp included traditional camp activities such as indoor rock climbing, participation on a challenge course, and crafts. Eighty percent of the campers indicated they now want to do a triathlon, and 95% shared that they will tell their friends about the sport of triathlon. Using the practitioner-friendly American Camp Association’s Youth Outcomes Battery, campers indicated gains in competence, teamwork, and problem-solving confidence. The findings of this evaluation study provide evidence-based support for the potential of triathlon camp to enhance important developmental outcomes. The results from the evaluation support the desired outcomes for this type of camp, and with USA Triathlon support, other recreation services can use this model to replicate. A unique aspect of this program was its setting and participant composition. That is, this day camp, hosted in an urban area, had a diverse group of campers with youth from various ethnic and sport backgrounds. Over half (60%) of the campers were of color, providing evaluation data from often underrepresented groups of interest. This program evaluation provides a template for other camps on campus model to focus on diversity, equity and inclusion of our youth. Currently, there is only one African American female professional triathlon in the United States. We need to be more intentional offering unique programs (e.g., triathlon camps and nonprofits) to all youth. Grants can be pursued by camps, municipal parks and recreation, nonprofits to remove some of the financial barriers preventing many youth of color from exploring the sport of triathlon.

Tooth color change promoted by different whitening toothpastes under alternate cycles of staining and brushing

ObjectivesTo compare the effect of whitening toothpastes with different mechanisms of action on discolored teeth subjected to additional staining/or not. MethodsOne hundred twenty tooth specimens were stained for 14 days (staining broth under constant agitation and pH=7) and then allocated into the groups of toothpastes with different whitening ingredients (n=10): 1. Regular - Colgate Total 12 Clean Mint; 2. CLWI - Colgate Luminous White Instant (blue pigment); 3. CLWA - Colgate Luminous White Advanced Expert (hydrogen peroxide); 4. CLWAC – Colgate Luminous White Activated Charcoal (activated charcoal); 5. OB3D – Oral-B 3D WHITE Brilliant Fresh (abrasive); 6. TW – Teeth Whitening (charcoal powder). Specimens were submitted to two experimental models: A. Daily staining-toothbrush cycling: staining solution (5min), toothbrushing (45 strokes) and artificial saliva (3h), 2x/day, for 5 days; B. Only toothbrushing (30.000 brushing strokes). Color change was determined with a spectrophotometer (CIEDE2000 and Whiteness Index for Dentistry - WID) and statistically analyzed (α=0.05). ResultsFor both models, ΔE00 and Δa did not differ significantly between the whitening toothpastes and the regular. All groups showed a decrease in tooth yellowness (-Δb) and an increase in WID. Group Teeth Whitening exhibited a decrease in luminosity (-ΔL). In model A, Groups did not differ significantly from the Regular in terms of ΔL (p=0.35) and Δb (p=0.74). Groups CLWI and OB3D exhibited a decrease in luminosity. Reduced redness (-Δa) occurred only in Group CLWI. In Model B, Groups OB3D (p=0.021) and CLWA (p=0.001) exhibited higher change in luminosity than in Group Teeth Whitening. All exhibited increased redness (+Δa) and lightness (+ΔL), except the Regular, CLWAC, and Teeth Whitening. Group OB3D had a significantly higher change in Δb than the Regular (p=0.021). ConclusionsIrrespective of the mechanism of action, all toothpastes reduced tooth yellowness and promoted similar overall color change. Exposure of the teeth to additional staining during the toothbrushing cycles did not influence the effect of the whitening toothpastes. Clinical SignificanceWhitening toothpastes should be tested in conditions that more closely simulate their use in a clinical scenario, in which alternate cycles of staining and brushing occur on a daily basis. However, even in such conditions, they were unable to promote a color change that differed from that of a regular toothpaste.

Fluorotic Enamel Susceptibility to Dental Erosion and Fluoride Treatment.

The purpose of this in vitro study was to test the hypothesis that fluoride treatment can prevent dental erosion on fluorotic enamel of different severities. It followed a 3×2 factorial design, considering a) fluorosis severity: sound (TF0, Thylstrup-Fejerskov Index), mild (TF1-2), moderate (TF3-4); and b) fluoride treatment: 0 (negative control) and 1150ppmF. Human molars with the three fluorosis severities (n=16, each) were selected and randomly assigned to the two fluoride treatments (n=8). Enamel blocks (4×4mm) were prepared from each tooth and subjected to a dental erosion cycling model, for 10 days. The daily cycling protocol consisted of erosive challenges (1% citric acid, pH 2.4), interspersed by periods of immersion in artificial saliva, and three 2-minute treatments with either 0 or 1150ppm F. The enamel volume loss (mm3) was calculated by subtracting values obtained by microtomography before and after cycling. Two-Way ANOVA showed no significant interaction between fluorosis severity and fluoride treatment (p=0.691), and no significant effect for either fluorosis severity (TF0 mean±standard-deviation: 13.5(10-2±0.42(10-2, TF1-2: 1.50(10-2±0.52(10-2, TF3-4: 1.24(10-2±0.52(10-2, p=0.416) or treatment (0ppmF: 1.49(10-2±0.53(10-2; 1150ppmF: 1.21(10-2±0.42(10-2; p=0.093), when evaluated independently. Considering the limitations of this in vitro study, the presence and severity of fluorosis in enamel do not appear to affect its susceptibility to dental erosion. Fluoride treatment was not effective in preventing the development of dental erosion in both sound and fluorotic enamel substrates under our experimental conditions.

Model Predictive Control Strategy for Residential Battery Energy Storage System in Volatile Electricity Market with Uncertain Daily Cycling Load

This paper presents a control strategy for residential battery energy storage systems, which is aware of volatile electricity markets and uncertain daily cycling loads. The economic benefits of energy trading for prosumers are achieved through a novel modification of a conventional model predictive control (MPC). The proposed control strategy guarantees an optimal global solution for the applied control action. A new cost function is introduced to model the effects of volatility on customer benefits more effectively. Specifically, the newly presented cost function models a probabilistic relation between the power exchanged with the grid, the net load, and the electricity market. The probabilistic calculation of the cost function shows the dependence on the mathematical expectation of market price and net load. Computational techniques for calculating this value are presented. The proposed strategy differs from the stochastic and robust MPC in that the cost is calculated across the market price and net load variations rather than across model constraints and parameter variations.

Cycling Assessment: A tool to inform policymakers and enhance the cyclist’s travel experience, with a gender perspective

Abstract Since 1998, Bogotá has consistently made substantial efforts to foster the bicycle’s role as a primary mode of transportation. Recent years have witnessed a compelling aspiration for the city to ascend as the “bicycle capital of the world,” evident in its accomplishment of 6.6% of daily trips completed by bicycle in 2019. This achievement translates to 880.367 daily cycling journeys (District Secretariat of Mobility of Bogotá, 2019). These statistics surpass regional benchmarks; for instance, other capital cities such as Santiago de Chile account for 510.569 bicycle trips, Mexico City for 433.981, and Rio de Janeiro for 217.000 (Ríos et al., 2015). Despite this progress, Bogotá lacks a comprehensive evaluation of both infrastructure quality and the user experience while cycling. This translational research article aimed to explore this gap by delving into the integration of user perceptions and experiences within the policy formulation process. This strategic approach is poised to enhance cycling’s allure as a mode of transportation for prospective cyclists while simultaneously maximizing the efficiency of investments in cycling infrastructure.

Keynote 2

Title of HEPA 2022 Keynote presentationPhysical activity, air pollution, and much more: the case for systems thinking in urban policies.Description of HEPA 2022 Keynote presentationPhysical activity may be one of greatest benefits of active travel -however there are many more, and in some cases there could be some trade-offs too. Yet, we create disjointed targets, campaigns and regulations to tackle in siloed and often piecemeal approaches major urban health and environmental challenges such as climate change, physical inactivity, air pollution, traffic injuries, social isolation, stress, inequalities, etc. The way we address these problems matters, and this lack of joined up thinking is a wasted opportunity. If we let the promotion of a healthier, more sustainable and resilient society be the goal of our policies rather than merely compliance with singularly focused standards and targets, we will find different types of solutions emerge as most advantageous. For example, in addition to providing a seamless way to integrate physical activity into daily routines, walking and cycling can be a convenient and low-cost alternatives to driving, thus reducing air pollution, green house gas emissions and noise; the infrastructure and urban design features conducive to walking and cycling may in turn have further benefits, such as traffic safety and greenspace exposure; etc. Evidence on benefits, co-benefits, and trade-offs of different types of urban policies that tackle some of our greatest urban health challenges jointly will be presented, making the case for holistic approaches to urban policy decision making, particularly through urban planning and design strategies. We will end by discussing avenues for greater integration of health in urban decision making.

The impact of the large-scale circulation anomalies in the northern hemisphere on air quality in Wuhan of China during the Spring Festival in 2020

During the 2020 Chinese Spring Festival extended holidays and the COVID-19 period in Wuhan, the “quasi-zero emissions increase” occurred due to the human activities have a considerably lower impact on air quality. A new scientific question of concern: Why has high of O3 and PM2.5 still been observed? The comparative analysis of the influences of anomalous atmospheric circulation and weather conditions during this special period in 2019–2020 with those in the historical years can be useful. The results in the study were as follows:(1) Even during this “quasi-zero emissions increase” period, the concentrations of O3 and PM2.5 are higher than normal, with O3 being significantly higher in Wuhan. Which is associated with a anomaly large-scale humid/warm water vapor transport in the Northern Hemisphere which is significantly different from that of the same period with historical more-haze years. (2) In this scenario, the large-scale humid/warm water vapor transport brings sustained high-humidity water vapor lifting conditions to north China. The daily cycling change of the sun's zenith angle to support the high-humidity and high-condensation condition are conducive to the elevation of high condensation (fc) and degree of super-saturation (S) going up to the peak of S >10%. Under the condition driven by high fc, it causes the power exponent law to be followed converting NO2 to O3, thereby resulting in an increase in O3 concentration. This additional contribution to O3 concentration is as high as 37% than those from pure chemical process. (3) An objective quantitative reversal method for calculating the monthly threshold in fc is given based on the power exponential conversion law by the observed data. It can be prospectively applied to assess the feedback on the impact of pollution on urban climate.

Osmoregulatory neurons clockwork is altered during metabolic disorder induced by high energy diet in the Sand rat Psammomys obesus

ABSTRACT Increasing evidences highlight the role of vasopressin (AVP) in the regulation of metabolic functions and the association between hydration state and metabolic disorders. Supraoptic nuclei (SON) neurons are particularly sensitive to metabolic changes, as shown by the loss of plasma AVP rhythmicity during diabetes. We aimed in this work to determine the effect of high energy (HE) feeding on SON clock functioning in Psammomys obesus, a desert herbivore rodent in which metabolic syndrome is nutritionally induced. Animals were subjected to either normal or HE feeding for 3 months. Immunohistochemical study indicates that AVP and the circadian transcription factor CLOCK profiles follow daily oscillations with higher content in the beginning of the rest period in control group fed with low energy (LE) diet. Our data show that HE feeding induces critical changes through impairment of daily AVP and CLOCK cycling in the SON. These findings show clearly that SON clockwork is altered by HE diet-induced metabolic changes. Further studies are needed to better understand SON neurons responses to metabolic derangement.

Meta-analysis of the effects of monensin on performance of beef replacement heifers and beef cows.

Although performance benefits of monensin have been extensively studied in finishing cattle, growing cattle, and dairy cows, considerably less published work is available evaluating response to monensin supplementation in cow-calf production systems. This meta-analysis investigated the impacts of monensin on performance of beef cows and developing replacement heifers. The replacement heifer analysis was conducted using data from 18 different peer-reviewed publications and experiment station reports. The mature cow analysis included 21 different publications and experiment station reports. The metaphor package (version 2.4-0; Viechtbauer, 2010) for R (version 4.0.3; www.r-project.org) was used to determine the overall effect size of monensin compared to a negative control. Each study’s n, means, and SEM or P value was used to calculate the mean difference and estimate of within study variance for responses of interest. In replacement heifers, monensin treatment increased (P < 0.01); average daily gain (+0.03 ± 0.008 kg/d), feed efficiency (+0.013 ± 0.008 gain:feed), and percentage cycling before the breeding season (+15.9 ± 5.13%); while decreasing (P < 0.01): dry matter intake (0.293 ± 0.081 kg), and age at puberty (‐8.9 ± 1.48 d). Six studies reporting ad libitum forage intake for mature cows showed decreased (P = 0.008) DMI by 0.85 ± 0.32 kg/d. Six studies reported milk yield and revealed an increase (P = 0.01) of 0.39 ± 0.15 kg/d when cows were supplemented with monensin. Monensin supplementation resulted in a reduction (P = 0.02) in days to first estrus by 18 ± 8.2 d and percentage of cows exhibiting estrus prior to the breeding season was increased by 19 ± 8% (P = 0.03). There were no differences in artificial insemination pregnancy nor total pregnancy for either the heifer or mature cow data sets. This analysis indicates potential for use of monensin in heifer development and beef cow production systems. Further research is needed to elucidate the effects on reproductive efficiency, DMI, milk production, weight, and body composition change.