Reduction In Mobility Research Articles

Mixed effects modelling of excess mortality and COVID-19 lockdowns in Thailand

Accurate mortality data are critical for understanding the impact of COVID-19 and learning lessons from crisis responses. But published statistics risk misrepresenting deaths due to limited testing, underreporting, and lack of subnational data, especially in developing countries. Thailand experienced four COVID-19 waves between January 2020 and December 2021, and used a color-coded, province-level system for lockdowns. To account for deaths directly and indirectly caused by COVID-19, this paper uses mixed effects modelling to estimate counterfactual deaths for 2020–2021 and construct a monthly time series of provincial excess mortality. A fixed effects negative binomial and mixed effects Poisson model both substantiate other studies’ estimates of excess deaths using subnational data for the first time. Then, panel regression methods are used to characterize the correlations among restrictions, mobility, and excess mortality. The regressions show that mobility reductions modestly curbed mortality immediately upon imposition, suggesting that aversion of non-COVID deaths was a major aspect of the lockdowns’ effect in Thailand. However, the estimates are imprecise. An auto-regressive distributed lag model suggests that the effect of lockdowns was through reduced mobility, but the effectiveness appears to have varied over the course of the pandemic.

Comparison of Laminectomy with Fusion and Laminoplasty Treating Multilevel Cervical Spondylotic Myelopathy: A Single-Center Retrospective Study

Comparing laminectomy with fusion (LF) and laminoplasty (LP) for treating multilevel cervical spondylotic myelopathy (MCSM) and comparative analysis of neck pain and sagittal cervical parameters. This single-center study retrospectively analyzed MCSM patients treated with LF or LP in our department between June 2018 and January 2023, with at least a 12-month follow-up. T-tests were used to identify operation time, hemoglobin, hospital stay, modified Japanese Orthopaedic Association (mJOA) score, C2-C7 Cobb angle, C2-C7 sagittal vertical axis, T1 slope, cervical range of motion (cROM), and C4/5 anterior and posterior spinal canal diameter (A-P diameter) and area. Nonparametric tests were used to identify visual analog scale (VAS) score (assessing neck pain). Pearson correlation analyses were used to identify the neck pain. Of all 67 patients (LF: 24, LP: 43), both groups' mJOA scores significantly improved (P<0.001). The VAS scores had both significantly decreased, with the LF group exhibiting a more marked reduction (LF: P<0.001, LP: P=0.037). Both groups' C4/5 A-P diameters and areas increased significantly (P<0.001). The cROM had both significantly decreased, with the LF group exhibiting a greater reduction. At the last follow-up, the LF group's T1 slope and C2-C7 Cobb angle considerably increased, and pain VAS scores substantially correlated with the C2-C7 Cobb angle (R=-0.451, P<0.001). LF and LP were efficacious for MCSM. LF relieved neck pain better but caused greater reduction in cervical mobility. Cervical lordosis improvement was significantly correlated with neck pain alleviation.

Experimental and data-driven analysis for predicting nanofluid performance in improving foam stability and reducing mobility at critical micelle concentration

Application of surfactant-based foam flooding is an effective approach to reduce mobility and control early breakthrough. Despite the proper performance of surfactant-based foams in decreasing the channeling of the flooded gas and water, high pressure, high temperature, and high salinity of the reservoirs put some limitations on the foam flooding efficiency. Nanoparticles are used to improve the quality of the foams, enhance stability, and transcend the limitations. Although there are many benefits of using nanoparticles in foam flooding, their performance at surfactant critical micelle concentration (CMC) is not fully investigated and the optimum nanoparticle concentration is not specified. In this study, an experimental investigation using nanosilica with surfactants at CMC to improve the stability (half-life) and mobility reduction factor (MRF) has been conducted. Furthermore, data from the literature were collected and analyzed to evaluate the change in MRF and stability for a nanofluid-based foam at CMC. Both experimental results and literature data showed that application of nanofluid-based foam is a successful approach to develop a more stable foam with lower mobility. Nanoparticle (NP) concentration is the dominant parameter at different salinities and temperatures that affects foam flow through porous media. The range of 0.2–0.4 wt% is the optimum nanoparticle concentration to develop a strong foam with acceptable performance in controlling mobility.

Ionic Conductivity of a Lithium-Doped Deep Eutectic Solvent: Glass Formation and Rotation-Translation Coupling.

Deep eutectic solvents with admixed lithium salts are considered as electrolytes in electrochemical devices, such as batteries or supercapacitors. Compared to eutectic mixtures of hydrogen-bond donors and lithium salts, their raw-material costs are significantly lower. Not much is known about glassy freezing and rotational-translation coupling of such systems. Here, we investigate these phenomena by applying dielectric spectroscopy to the widely studied deep eutectic solvent glyceline, to which 1 and 5 mol % LiCl were added. Our study covers a wide temperature range, including a deeply supercooled state. The temperature dependences of the detected dipolar reorientation dynamics and ionic direct current (dc) conductivity reveal the signatures of glassy freezing. In comparison to pure glyceline, the lithium admixture leads to a reduction of ionic conductivity, which is accompanied by a reduction of the rotational dipolar mobility. However, this reduction is much smaller than that for deep eutectic solvents (DESs), where one main component is lithium salt, which we trace back to the lower glass-transition temperatures of lithium-doped DESs. In contrast to pure glyceline, the ionic and dipolar dynamics become increasingly decoupled at low temperatures and obey a fractional Debye-Stokes-Einstein relation, as previously found in other glass-forming liquids. The obtained results demonstrate the relevance of decoupling effects and glass transition to the enhancement of the technically relevant ionic conductivity in such lithium-doped DESs.

327 Sustained Improvement in Compliance With Use of Sequential Compression Devices in a Neurosurgery Patient Population of a Safety-Net Hospital

INTRODUCTION: Sequential Compression Devices (SCDs) are utilized in perioperative patients given increased risks of deep venous thrombosis from mobility reductions and post-operative inflammatory responses. Additionally, mechanical prophylaxis is crucial in patients where chemical prophylaxis is contraindicated. Previous work has found SCD compliance far less than expected. METHODS: Across a 9-month period (August-April), we tracked which neurosurgical patients in stepdown units had SCDs on and properly functioning. When not on or properly functioning, we documented the missing element. Compliance was calculated daily as the percentage of patients who were SCD compliant out of all patients with SCD orders, then averaged over the month, for each month. Most common barriers to compliance were identified. Together with nursing management, we designed and implemented a best practice alert to facilitate nursing education and supply chain management, at month 3. The impact was tracked over the next six months, with a 4-months break from November-February. RESULTS: Compliance averaged 19.7% (n = 95) during August, and 38.4% (n = 131) in September. After implementation of the best practice nursing alert and supply chain upgrades, compliance was 48.8% (n = 150) in October, 41.2% (n = 104) in March, and 45.9% (n = 76) in April. Residual barriers to compliance included patient behavior and equipment issues. Compliance was significantly increased from baseline in August to October (z = 5.042). The significant difference was sustained through March (z = 3.402) and April (z = 3.730). CONCLUSIONS: While initial improvement was attributed to a Hawthorne effect, implementation of the best practice nursing alert likely facilitated the sustained improvement in SCD compliance despite the break in surveillance. SCD compliance nonetheless remained below 50%. Further study is warranted to address the remaining barriers, such as improving patient engagement and minimizing equipment malfunction.

The Impact of Physiotherapy on the Developmental Progress of Preterm Infants Hospitalized in the Intensive Care Unit

Introduction: Every year, worldwide, 14.9 million babies are born prematurely. Therefore, these children are at greater risk of respiratory, cardiac, and neurodevelopmental disorders. Purpose: The purpose of the study was to investigate the effectiveness of physiotherapy intervention in premature newborns and whether the utilized techniques promote their normal development Patients: the study population consisted of 20 randomly selected neonates. The 20 neonates were randomly divided into two groups, the intervention group (Group A, 10 neonates) and the control group (Group B, 10 neonates). Methods: In the newborns of the intervention group (A), an intervention was carried out that focused on the correct positioning in a "nest" (imitation of intrauterine experience), on the changes of supine, prone, right, and left side positions, on the reduction or elimination of stress signs and passive mobilization in the supine position. Oxygen saturation (SpO2) and heart rate were continuously recorded, as well as neurodevelopmental assessment and recording of any feeding problems. weight gain, but also the length of stay of newborns in the hospital. Results: Oxygen saturation was clearly improved in premature neonates who followed respiratory physical therapy as well as improved (decreased) heart rate. Neurological examination in the neonates of the intervention group was normal and none showed feeding problems. It was also found that the newborns in the intervention group had a more stable rate of weight gain compared to the newborns in the control group. Conclusions: It is considered necessary to implement early intervention programs to prevent or minimize the negative effects of prematurity on the respiratory and neurodevelopmental development of newborns

Electric partial discharges in biodegradable oil-based ferrofluids: A study on effects of magnetic field and nanoparticle concentration

This paper presents an experimental study of partial discharge activity in ferrofluids based on biodegradable transformer oil and iron oxide nanoparticles. Three ferrofluid samples with low, medium and high nanoparticle concentrations are employed in the research. The basic ferrofluid characterization is followed by a partial discharge experiment exposing the ferrofluids to a high voltage in a needle-plate electrode configuration. The analysis confirms that the apparent charge and number of discharges decrease with increasing nanoparticle concentration. These findings are interpreted with reference to the well-recognised electro-hydrodynamic streamer model. The charge trapping by nanoparticles hinders the ionization and discharge development. The study also focuses on the partial discharge activity in the ferrofluids under the action of a static magnetic field acting perpendicularly to the electric field. A decreasing trend in the number of discharges due to the magnetic field is revealed. A qualitative explanation is provided based on the field-induced cluster formation and charge mobility reduction. The presented experiment and the discussed findings may be valuable for practical application of the ferrofluid in high voltage equipment with a special need for partial discharge suppression.

Assessment of aluminium toxicity on Dugesia tigrina: implications for reproduction, behaviour, and enzymatic metabolism

ABSTRACT Aluminium (Al) is the eighth most prevalent metallic contaminant in global aquatic environments. This study explores the toxicity of Al and the acidity generated in the aquatic environment, using Dugesia tigrina, elucidating its environmental repercussions. The research uniquely highlights reproductive, behaviours and enzymatic effects pertinent to Al toxicity. The paper evaluated median lethal concentration [LC50 (96 h)], planarian mobility (pLmV), reproductive effects, glycogen content, and enzymes activities. The LC50 (96 h) was 348.08 µM. The aqueous extract produced a 74.6% reduction in mobility after acute exposition, and a 34.3% decrease in glycogen content after 14 days at 100 µM Al. Fertility and fecundity decreased by 47.8% and 67.8%, respectively, after 30 days at 50 µM Al (pH 7.0), with a complete absence of cocoons at pH 5.9. Hatching time increased by 24.8% at 50 µM Al (pH 7.0). Exposure to 100 µM Al for 24 h increase enzyme activities: catalase (49%), superoxide dismutase (89.7%), and acetylcholinesterase (46%). The observed changes in enzyme activity underscore Al's adverse effects on reproduction, behaviour, and enzymatic metabolism in planarians, urging the implementation of effective environmental management strategies to mitigate potential implications for various species and ecosystems.

Local-scale phylodynamics reveal differential community impact of SARS-CoV-2 in a metropolitan US county.

SARS-CoV-2 transmission is largely driven by heterogeneous dynamics at a local scale, leaving local health departments to design interventions with limited information. We analyzed SARS-CoV-2 genomes sampled between February 2020 and March 2022 jointly with epidemiological and cell phone mobility data to investigate fine scale spatiotemporal SARS-CoV-2 transmission dynamics in King County, Washington, a diverse, metropolitan US county. We applied an approximate structured coalescent approach to model transmission within and between North King County and South King County alongside the rate of outside introductions into the county. Our phylodynamic analyses reveal that following stay-at-home orders, the epidemic trajectories of North and South King County began to diverge. We find that South King County consistently had more reported and estimated cases, COVID-19 hospitalizations, and longer persistence of local viral transmission when compared to North King County, where viral importations from outside drove a larger proportion of new cases. Using mobility and demographic data, we also find that South King County experienced a more modest and less sustained reduction in mobility following stay-at-home orders than North King County, while also bearing more socioeconomic inequities that might contribute to a disproportionate burden of SARS-CoV-2 transmission. Overall, our findings suggest a role for local-scale phylodynamics in understanding the heterogeneous transmission landscape.

α‐TeO2 Oxide as Transparent p‐Type Semiconductor for Low Temperature Processed Thin Film Transistor Devices

AbstractIn comparison to reports on n‐type semiconducting oxides, p‐type oxide semiconducting materials are still rare. Scarcely reported p‐type oxide transistors demonstrated unsatisfactory environmental stability which still hinders their implementation for all oxide transistors and circuit applications. In this study, for the first time on α‐TeO2 as an active channel material with p‐type characteristics accessible by direct evaporation technique. Notably, the fabricated 5 nm α‐TeO2 thin film in connection with an equally thin passivation layer exhibits a remarkable low processing temperature of 50 °C generating a hole mobility of 3.8 cm2 V−1 s−1, an on‐state current of 966 µA, and an on/off ratio of 3.8 × 103. Additionally, the reproducibility of these devices confirmed a narrow variation in the TFT metrics, yielding an average hole mobility, on‐current, and on/off ratio of 3.59 cm2 V−1 s−1, 914 µA, and 3.3 × 103, respectively. Furthermore, the devices are subjected to extensive stability testing under ambient atmospheric conditions that exhibits a marginal mobility reduction while maintaining a stable on/off ratio over 125‐day period, highlighting their robust environmental stability. Notably, the low processing temperatures with both exceptional transistor performance and environmental endurance makes them suitable for the integration onto flexible substrates, particularly bendable/stretchable displays.

Effect of sulphonated naphthalene formaldehyde superplasticizer on the mechanical and durability properties of concrete produced using locally sourced fine aggregate from Ghana

The use of superplasticizers is very uncommon in many developing countries. However, its inclusion in concrete enhances concrete's mechanical and durability properties. There is a yawning gap in the literature on the performance of Sulphonated Naphthalene Formaldehyde (SNF) superplasticizers in concrete, especially in the sub-Saharan construction industry where the quality of aggregates used in production is questionable. This study produced two batches of concrete produced with locally sourced pit sand, with characteristic strength of 30 MPa. One batch was without the SNF superplasticizer to serve as a control, whereas the other batch was made with the incorporation of the superplasticizer. The fresh properties of slump and air content and the hardened properties of compressive and flexural strength, elastic, and dynamic moduli were investigated. Further, durability indicators comprising sorption, water absorption, sorptivity, chloride penetration, electrical surface resistivity, and acid attack were investigated. The results of the study demonstrated that the incorporation of SNF superplasticizers in concrete resulted in improved workability and a reduction in ion mobility within the concrete. This was attributed to a decrease in the presence of interconnected pores, leading to notable enhancements in mechanical properties such as increased strength, as well as improvements in both elastic and dynamic moduli. Moreover, concrete containing SNF superplasticizer protects the concrete much better from acid attack than those without SNF superplasticizer. The study recommends the use of SNF superplasticizers in concrete for improved workability, reduced ion movement via fewer interconnected pores, and enhanced mechanical properties, potentially boosting overall durability.

An Updated Overview of Risk Factors for Shoulder Stiffness.

A painful reduction in shoulder mobility, known as "shoulder stiffness", can occur both as a primary idiopathic condition and as a secondary condition, for example, following surgical procedures. Various factors can contribute to the development of primary shoulder stiffness. In this review we summarize the pathophysiological mechanisms, genetic influences, endocrine disorders, metabolic conditions, as well as other diseases and medical-therapeutic approaches that might have an impact on the development of primary shoulder stiffness.

Methane foam performance evaluation in fractured oil-wet carbonate systems at elevated pressure and temperature conditions

This study investigates the potential of foam flooding for enhanced oil recovery in oil-wet fractured systems under reservoir conditions. Two surfactants with distinct ionic properties were employed in combination with methane to generate foam via simultaneous injection into propped fractures, aiming to optimize the diversion of gas from fractures to the matrix for improved oil recovery. Core flooding experiments demonstrated the critical roles of total injection rate and foam quality in controlling foam performance. Increasing the total injection rate from 1 to 3 cm³/min enhanced foam generation rates and foam lamella stability, facilitating better interactions between fractures and the matrix. However, beyond an injection rate of 4 cm³/min, there was a decline in apparent viscosity and mobility reduction factor. Foam strength was directly proportional to higher foam quality within the 50 to 80% range, but beyond 85% foam quality, fluctuations in pressure drop signaled the formation of weaker, less stable foams. Micro-scale experiments validated these macroscopic findings, revealing that smaller bubbles were associated with higher flow rates and lower foam qualities. This research contributes valuable insights into both micro and macro-scale in-situ foam generation, which can inform the design and application of foam-based enhanced oil recovery methods in fractured reservoirs.

Mobility restrictions in response to local epidemic outbreaks in rock-paper-scissors models

We study a three-species cyclic model whose organisms are vulnerable to contamination with an infectious disease which propagates person-to-person. We consider that individuals of one species perform a self-preservation strategy by reducing the mobility rate to minimise infection risk whenever an epidemic outbreak reaches the neighbourhood. Running stochastic simulations, we quantify the changes in spatial patterns induced by unevenness in the cyclic game introduced by the mobility restriction strategy of organisms of one out of the species. Our findings show that variations in disease virulence impact the benefits of dispersal limitation reaction, with the relative reduction of the organisms’ infection risk accentuating in surges of less contagious or deadlier diseases. The effectiveness of the mobility restriction tactic depends on the deceleration level and the fraction of infected neighbours which is considered too dangerous, thus triggering the defensive strategy. If each organism promptly reacts to the arrival of the first viral vectors in its surroundings with strict mobility reduction, contamination risk decreases significantly. Our conclusions may help biologists understand the impact of defensive strategies in ecosystems during an epidemic.

Consumer purchase response to e-bike incentives: Results from a nationwide stated preference study

Electric bike (e-bike) incentives are gaining popularity to increase ownership of e-bikes, with goals of increased mobility while reducing emissions. This study is among the first to experimentally analyze prospective purchase behavior of e-bike consumers to assess price sensitivity, behavioral response to incentives, and consumer value of e-bike attributes. We present results of a nationwide (20 cities) stated-preference survey and find e-bike incentives are powerful levers to shift behavior. Different incentive mechanisms have different behavioral utility. Point-of-purchase discounts are the most influential at shifting behavior, followed by tax credits, then mail-in rebates. Point-of-purchase discounts are 30% more effective than mail-in rebates. Across point-of-purchase scenarios, the average inframarginal cost of an added e-bike purchase is $4252 (range $3719 to $4799). Income-based schemes that are often aimed at increasing equity result in cost-effectiveness trade-offs. Policy makers should evaluate the investment in e-bike purchase incentives across benefits from added e-bike ownership that include not only greenhouse gas reductions, but also health benefits, increased mobility, travel affordability, safety, and congestion reductions.

Air quality and urban climate improvements in the world’s most populated region during the COVID-19 pandemic

In this study, we assessed air quality (AQ) and urban climate during the mobility restrictions implemented in the Greater Tokyo Area, Japan, the world’s most populated region, in response to the COVID-19 pandemic. Observations from dense surface networks were analyzed using an interpretable machine learning approach. In parallel with a ∼50% reduction in mobility and an altered lifestyle of the population, we found limited reductions in nitrogen dioxide; decreases in fine particulate matter not entirely driven by local mobility; minor variations in ozone, with a positive (negative) tendency in areas with high (low) emissions; a decrease in air temperature consistent with mobility; and pollution levels and air temperature changes with well-defined, common spatiotemporal patterns. Specifically, cooling mainly occurred in urbanized areas with an improved AQ. Overall, although reductions in mobility were moderately effective in improving the typical indicators of urban AQ, including those known to negatively impact human health, the reductions in waste heat had a stronger impact on Tokyo’s urban heat island, suggestive of a strategy to minimize exposure to heat stress. These findings can help guide urban planning strategies and policies aimed at addressing climate change.

Assessment of World’s First Two Polymer Injectivity Tests Performed in Two Giant High-Temperature/High-Salinity Carbonate Reservoirs Using Single-Well Simulation Models and Pressure Falloff Tests Analysis

Summary Polymer flooding is a mature enhanced oil recovery (EOR) technology that has been widely implemented around the world for more than 60 years. Polymer flooding mostly targets medium- to high-permeability sandstone reservoirs with moderate salinity, hardness, and temperatures. However, in the last few years, the envelope of polymer flooding has been expanded to harsher reservoir conditions of high-temperature and high-salinity mixed-wet to oil-wet heterogeneous carbonate reservoirs. Development of novel polymers and innovative field application concepts has allowed for the reconsideration of polymer-based EOR as a promising technology to improve sweep efficiency for these challenging reservoirs. Polymer injectivity is one of the key challenges for polymer flooding projects and requires a rigorous derisking program that includes laboratory and field testing. A comprehensive laboratory program was designed to assess and investigate polymer thermal stability, polymer rheology in porous media, adsorption, and injectivity using reservoir core samples. In addition, two polymer injectivity tests (PITs) were performed in two giant light oil (0.3 cp) carbonate reservoirs in onshore Abu Dhabi under harsh conditions of high salinity (&amp;gt;200 g/L), high divalent ions (&amp;gt;20 g/L), high temperature (&amp;gt;250°F), and H2S concentration of up to 40 ppm. The polymer used during the two PITs (PIT 1 2019 and PIT 2 2021) is a new generation of EOR polymer (SAV 10) with high 2-acrylamido-tertiary-butyl sulfonic acid content that was specifically developed to tolerate such harsh conditions. This paper is focused on the interpretation of the PITs and lessons learned for future polymer-based EOR projects. The detailed data acquired in both tests were used to evaluate the polymer injectivity at representative field conditions and in-depth mobility reduction. The PITs together with the extensive laboratory studies are part of a thorough derisking program for the upcoming world’s first innovative hybrid EOR multiwell pilots—simultaneous injection of miscible gas and polymer (SIMGAP) and simultaneous injection of water and polymer (SIWAP). Both PITs are composed of three stages that include a multirate waterflood baseline, polymer injection using different rates, and polymer concentrations followed by extended chase waterflooding. In addition, a sequence of multiple pressure falloff (PFO) tests was acquired during the PIT executions and analyzed to obtain the required uncertainty parameters for the history-matching exercise. Polymer preshearing was considered as part of both PIT programs with the aim to homogenize the polymer molecular weight distribution and reduce possible shear-thickening effects near the wellbore as per laboratory measurements. Two single-well 3D simulation models were built to incorporate the information from polymer laboratory studies and to interpret the large field data sets acquired during the PITs. Lessons learned from PIT 1 allowed us to optimize the PIT 2 design program and achieve better understanding of polymer characteristics. The interpretation of the pressure transient analysis (PTA) of the PFO tests and the 3D simulation models of the two PITs confirmed the generation of polymer banks and demonstrated effective propagation of the polymer into the reservoirs at target concentrations and representative rates of the future SIWAP and SIMGAP interwell pilots.

Exploring the dynamics and structure of PpiB in living Escherichiacoli cells using electron paramagnetic resonance spectroscopy.

The combined effects of the cellular environment on proteins led to the definition of a fifth level of protein structural organization termed quinary structure. To explore the implication of potential quinary structure for globular proteins, we studied the dynamics and conformations of Escherichia coli (E. coli) peptidyl-prolyl cis/trans isomerase B (PpiB) in E. coli cells. PpiB plays a major role in maturation and regulation of folded proteins by catalyzing the cis/trans isomerization of the proline imidic peptide bond. We applied electron paramagnetic resonance (EPR) techniques, utilizing both Gadolinium (Gd(III)) and nitroxide spin labels. In addition to using standard spin labeling approaches with genetically engineered cysteines, we incorporated an unnatural amino acid to achieve Gd(III)-nitroxide orthogonal labeling. We probed PpiB's residue-specific dynamics by X-band continuous wave EPR at ambient temperatures and its structure by double electron-electron resonance (DEER) on frozen samples. PpiB was delivered to E. coli cells by electroporation. We report a significant decrease in the dynamics induced by the cellular environment for two chosen labeling positions. These changes could not be reproduced by adding crowding agents and cell extracts. Concomitantly, we report a broadening of the distance distribution in E. coli, determined by Gd(III)-Gd(III) DEER measurements, as compared with solution and human HeLa cells. This suggests an increase in the number of PpiB conformations present in E. coli cells, possibly due to interactions with other cell components, which also contributes to the reduction in mobility and suggests the presence of a quinary structure.

Characterizing collective physical distancing in the U.S. during the first nine months of the COVID-19 pandemic.

The COVID-19 pandemic offers an unprecedented natural experiment providing insights into the emergence of collective behavioral changes of both exogenous (government mandated) and endogenous (spontaneous reaction to infection risks) origin. Here, we characterize collective physical distancing-mobility reductions, minimization of contacts, shortening of contact duration-in response to the COVID-19 pandemic in the pre-vaccine era by analyzing de-identified, privacy-preserving location data for a panel of over 5.5 million anonymized, opted-in U.S. devices. We define five indicators of users' mobility and proximity to investigate how the emerging collective behavior deviates from typical pre-pandemic patterns during the first nine months of the COVID-19 pandemic. We analyze both the dramatic changes due to the government mandated mitigation policies and the more spontaneous societal adaptation into a new (physically distanced) normal in the fall 2020. Using the indicators here defined we show that: a) during the COVID-19 pandemic, collective physical distancing displayed different phases and was heterogeneous across geographies, b) metropolitan areas displayed stronger reductions in mobility and contacts than rural areas; c) stronger reductions in commuting patterns are observed in geographical areas with a higher share of teleworkable jobs; d) commuting volumes during and after the lockdown period negatively correlate with unemployment rates; and e) increases in contact indicators correlate with future values of new deaths at a lag consistent with epidemiological parameters and surveillance reporting delays. In conclusion, this study demonstrates that the framework and indicators here presented can be used to analyze large-scale social distancing phenomena, paving the way for their use in future pandemics to analyze and monitor the effects of pandemic mitigation plans at the national and international levels.

Spatial–Temporal Urban Mobility Pattern Analysis During COVID-19 Pandemic

In response to the repeated outbreaks of the COVID-19, many countries implement the region-specific, multilevel epidemic prevention and control policies. To fully understand the impact of these interventions on urban mobility, it is urgent to analyze spatial–temporal mobility pattern at the neighborhood level and structural changes in urban mobility networks. Here, we construct urban mobility networks among points of interest (POIs), using large-scale anonymous mobility data from de-identified mobile phone users. We comprehensively investigate the changes of urban mobility networks during two waves of the COVID-19 pandemic in Beijing from both graph and subgraph perspectives. Beyond an overall mobility reduction in Beijing, we find that the mobility change is spatially and temporally heterogeneous among different urban regions. We uncover a disproportionately large reduction in long-distance, nighttime, and non-essential travel. This results in a more geographically fragmented, local, and regional network in the pandemic. We demonstrate that these structural changes slow down the spatial spread of the COVID-19 in the mobility network.