Search

Moderation analysis for evaluating differential treatment effects serves as the bedrock of precision medicine, which is of growing interest in many fields. In the analysis of data with binary outcomes, we observe an interesting symmetry property concerning the ratio of odds ratios, which suggests that heterogeneous treatment effects could be equivalently estimated via a role exchange between the outcome and treatment variable in logistic regression models. We then obtain refined inference on moderating effects by rearranging data and combining two models into one via a generalized estimating equation approach. The improved efficiency is helpful in addressing the lack-of-power problem that is common in the search for important moderators. We investigate the proposed method by simulation and provide an illustration with data from a randomized trial on wart treatment.

The aim of this work is to develop materials that can absorb microwave to meet the requirements of stealth technology and solve the problem of electromagnetic pollution. However, the challenge is having materials with high-efficient absorption properties at an ultralow filling rate and visualizing the microwave response. The strategy used in this work was to integrate point defect and microstructure in preparing materials, nitrogen-doped reduced graphene oxide@ carbon nanofibers with high-efficient microwave absorption and double-layered structure. Ethylenediamine (nitrogen source), was doped into the materials, resulting in the generation of the defects. The microwave absorption performance of the materials was affected by the degree of defects due to the dipole polarization loss and conductive loss. The optimal samples gained the maximum reflection loss of -54.7 dB and effective absorption bandwidth of 4.74 GHz at a filling rate of only 8 wt%. More significantly, the microwave absorbing mechanism was analyzed visually in the response field. Furthermore, the actual stealth effects were evaluated by the radar cross section reduction, and the value was 29.2 dBm

As a response to stealth technology and electromagnetic pollution, microwave absorbing materials have attracted the attention of many research scholars. However, achieving effective absorption with a low filling level is still a challenge in the harsh environment. Here, an emerging carbon-carbon composite fiber with a core-sheath structure is cleverly tailored for high-performance microwave absorber by tuning the dielectric loss. Reasonable engineering heterogeneous interfaces and conductive paths give rise to a synergistic effect of the impedance matching, conductive loss, polarization loss and multiple scattering. The obtained CR-800 achieves the maximum reflection loss of -51.91 dB, effective absorbing bandwidth of 4.82 GHz, and radar cross section (RCS) reduction value of 41.5 dBm

Fe–Ni nanoparticle–decorated LaSr(Fe,Mo)O4 Ruddlesden–Popper (R–P) perovskite anodes, named R–LSFMNx, were prepared in situ by reducing perovskites La0.5Sr0.5Fe0.9Mo0.1–xNixO3–δ (LSFMNx; x = 0.03–0.07) under SOFC anode operating conditions. Electrolyte–supported single cells with a configuration of R–LSFMNx|La0.9Sr0.1Ga0.8Mg0.2O3–δ (LSGM)|Ba0.5Sr0.5Co0.9Nb0.1O3–δ were used to evaluate the electrochemical performances and redox/long–term stability of the R–LSFMNx anodes fuelled by H2, CO, and simulated syngases (x% H2/CO; x = 50–10). EIS analyses indicated that the increased Ni level in the exsolved Fe–Ni nanocatalysts significantly promotes fuel diffusion/adsorption/dissociation, which plays a rate–limiting role in the anode fuel oxidation. Furthermore, the incremental Ni in Fe–Ni alloy also enhances the anode redox/long–term stability and carbon resistance/tolerance, and the R–LSFMN0.07 anode, i.e., Ni level in Fe–Ni alloy attaining ∼14 mol.%, displays the optimal stability and carbon resistance/tolerance. Finally, the potential of the R–LSFMN0.07 anode for direct utilization of syngas was demonstrated by the characterization of the electrochemical performance and stability based on the R–LSFMN0.07 anode cell.

Cobalt–free perovskites Ln0.5Sr0.5Fe0.9Mo0.1O3–δ (Ln = lanthanide; LnSFM) were prepared via a sol–gel process. Pure rhombohedral phases were still not obtained for the samples (Ln = Sm and Gd) even sintered at 1300 °C. Thus, only the LaSFM, PrSFM and NdSFM compositions were assessed as IT–SOFC cathodes in terms of their thermal, electrical and electrochemical properties. Thermal expansion of the LnSFM was well compatible with that of Sm0.2Ce0.8O1.9 (SDC) electrolyte. Both conductivity and electrochemical performances of the LnSFM followed the same sequence of La > Nd > Pr. For the LaSFM, NdSFM and PrSFM cathodes, peak conductivities reached 73, 63 and 59 S·cm–1 at 650 °C; polarization resistances attained 0.211, 0.446 and 0.469 Ω·cm2 at 700 °C; peak power densities of the LnSFM cells with 300–μm–thick SDC electrolyte achieved 269, 261 and 233 mW·cm–2 at 700 °C without cell degradation for operating 100 h. By comprehensive comparison, the LaSFM is assessed as a preferred cobalt–free ceramic cathode for IT–SOFC.

Currently, microwave absorbers have received much attention in the military and civil fields on account of electromagnetic radiation and stealth technology. Herein, NiCo2O4/Graphite nanosheets/NiCo2O4 (GNC) hybrid composites with sandwich-like heterostructures were carefully constructed using a hydrothermal method and subsequent annealing process. The morphology and microwave absorption performance are investigated by changing the additive amount of GNS to regulate the ratio of GNS/NiCo2O4. The results show that varying the ratio of GNS/NiCo2O4 has a tiny effect on its structure, nanoband-like NiCo2O4 with the width of 100 nm attaches to the surface of GNS, while it can well tune the microwave absorption properties. When the additive amount of GNS increases from 0.02 g to 0.04 g, the microwave absorption performance first improves and subsequently worsens, which is attributed to the effect of impedance matching and attenuation capacity that resulted from conductive loss, interface polarization, and charge polarization. When the additive amount of GNS is 0.03 g, the maximum reflection loss and effective absorption bandwidth of GNC-2 composites are −47.01 dB and 2.98 GHz (14.51–17.49 GHz) with a thickness of 1 mm. Our results can provide more information for the design and manufacture of composites based on graphite nanosheets as high-performance microwave absorbers.

The increasing use of advanced technologies in the civil and military fields has led to electromagnetic pollution. Thus, microwave absorbing materials that can transform electromagnetic energy into other forms of energy have been extensively investigated to limit the electromagnetic pollution. Herein, the CoFe2O4/FeCo/graphite nanosheets (CFG) hybrid composites were prepared by a one-step and facile liquid reduction method and the microwave absorption performances of the composites were investigated. The impedance matching and attenuation ability of the composites could be well tuned by varying the filling ratio of CFG in the matrix. Accordingly, high microwave absorption performances could be achieved. At a filling ratio of 50 wt% (CFG-50), a maximum reflection loss of −54.3 dB at a thin thickness of 1.2 mm and an effective absorption bandwidth of 4.08 GHz at a thin thickness of 1.3 mm were achieved. Notably, in the thickness range of 1.2–5.5 mm, the effective absorption bandwidth reached up to 15.2 GHz (2.8–18 GHz), covering the entire C, X, and Ku bands. The excellent microwave absorption properties were attributed to the moderate impedance matching and attenuation capacity caused by the dielectric loss, magnetic loss, multiple reflection, and scattering. The attractive features of CFG-50: remarkable absorption, broad bandwidth, low thickness, and fast preparation make it highly suitable for practical microwave absorbing applications.

In meta-analysis, heterogeneity often exists between studies. Knowledge about study features (i.e., moderators) that can explain the heterogeneity in effect sizes can be useful for researchers to assess the effectiveness of existing interventions and design new potentially effective interventions. When there are multiple moderators, they may amplify or attenuate each other’s effect on treatment effectiveness. However, in most meta-analysis studies, interaction effects are neglected due to the lack of appropriate methods. The method meta-CART was recently proposed to identify interactions between multiple moderators. The analysis result is a tree model in which the studies are partitioned into more homogeneous subgroups by combinations of moderators. This paper describes the R-package metacart, which provides user-friendly functions to conduct meta-CART analyses in R. This package can fit both fixed- and random-effects meta-CART, and can handle dichotomous, categorical, ordinal and continuous moderators. In addition, a new look ahead procedure is presented. The application of the package is illustrated step-by-step using diverse examples. Electronic supplementary material The online version of this article (10.3758/s13428-020-01360-0) contains supplementary material, which is available to authorized users.

In recent years, the high-performance microwave absorbers with strong loss, broad frequency bandwidth, thin thickness and light weight have been intensively investigated to address the problem of electromagnetic pollution and improve stealth technology. Considering the fact that microwave absorption performance is quite sensitive to morphology, studying NiCo2O4 with different morphologies is a valuable step towards developing a high-performance microwave absorber. The different morphologies are prepared by adjusting the addition of the structure-directing agent NH4F. When the amount of added NH4F is 1 mmol, a flower-like NiCo2O4 morphology (NC–F1) is obtained with a large specific surface area of 158.97 m2/g and pore volume of 0.3525 cm3g-1, which easily generates conductive loss, polarization loss, and multiple scattering, thereby enhancing its microwave absorption performance. The maximum reflection loss reaches −50.3 dB at 3 mm, and the effective bandwidth is 4 GHz with the matching thickness of 2 mm when the fill ratio is only 30 wt% in the epoxy resin. As the thicknesses range from 1.5 mm to 5 mm, the effective bandwidth is 14.2 GHz (3.8 GHz–18 GHz) and covers the entire C, X, and Ku bands. Therefore, the defined-morphology NiCo2O4 is expected to be a novel wide-band and strong-loss microwave absorber.

Recurrent event data are commonly encountered in biomedical studies. In many situations, they are subject to an informative terminal event, for example, death. Joint modeling of recurrent and terminal events has attracted substantial recent research interests. On the other hand, there may exist a large number of covariates in such data. How to conduct variable selection for joint frailty proportional hazards models has become a challenge in practical data analysis. We tackle this issue on the basis of the "minimum approximated information criterion" method. The proposed method can be conveniently implemented in SAS Proc NLMIXED for commonly used frailty distributions. Its finite-sample behavior is evaluated through simulation studies. We apply the proposed method to model recurrent opportunistic diseases in the presence of death in an AIDS study.

In this paper, we propose a new random forest method based on completely randomized splitting rules with an acceptance–rejection criterion for quality control. We show how the proposed acceptance–rejection (AR) algorithm can outperform the standard random forest algorithm (RF) and some of its variants including extremely randomized (ER) trees and smooth sigmoid surrogate (SSS) trees. Twenty datasets were analyzed to compare prediction performance and a simulated dataset was used to assess variable selection bias. In terms of prediction accuracy for classification problems, the proposed AR algorithm performed the best, with ER being the second best. For regression problems, RF and SSS performed the best, followed by AR, and then ER at the last. However, each algorithm was most accurate for at least one study. We investigate scenarios where the AR algorithm can yield better predictive performance. In terms of variable importance, both RF and SSS demonstrated selection bias in favor of variables with many possible splits, while both ER and AR largely removed this bias.

The rGO-wrapped nanocomposites can be regarded as promising candidates for the development of advanced microwave absorbing materials. In this work, hierarchical rGO-wrapped CNFs were prepared via a two-step strategy, including a classical modified Hummers method and a green reduction reaction. Accompany with the chemical treatments, graphene oxide appears on the outer walls of carbon nanofibers. By modulating the addition amount of ascorbic acid, the outer graphene oxide can be controllably reduced. Moreover, the CNFs/rGO with proper reduction degree exhibits desirable microwave absorption performance, whose minimum RL and effective bandwidth are −38.1 dB (3.85 GHz, d = 5.0 mm) and 4.1 GHz (5.08–9.18 GHz, d = 3.5 mm). The superior microwave attenuation performance is attributed to the synergistic effects between the CNFs and rGO. While the nanofibers provide the obtained sample with an extremely long conductive network, rGO introduces a moderate amount of lattice defects and functional groups, resulting in desirable conductivity loss and multiple polarizations. The existence of rGO also endows CNFs/rGO with suitable dielectric values so that the absorber achieves well impedance matching. Considering the excellent microwave absorption performance, this research provides a new facile route to fabricate rGO-wrapped carbonaceous materials with proper oxygen-containing groups for MAMs.

In order to reduce the radiation and interference of electromagnetic waves, rational assembly of dielectric materials and magnetic materials is becoming a promising strategy to produce highly efficient microwave absorbers. Herein, a novel kind of ternary nanocomposites, multi-wall carbon nanotubes decorated plate-like BaFe12O19@ZnFe2O4 (BaFe12O19@ZnFe2O4/MWCNTs), was fabricated via a two-step method. Plate-like BaFe12O19 was prepared firstly as a template for the growth of ZnFe2O4 layer, forming a core-shell structure. MWCNTs dispersed between BaFe12O19@ZnFe2O4 particles and ZnFe2O4 microspheres, forming three-dimensional (3D) conductive networks. The careful design of the structure and the combination of the dielectric material with the hard-soft magnetic material caused excellent impedance matching and multiple loss mechanisms, which endow the ternary hybrids with remarkable microwave absorption performance. The minimum reflection loss reaches −42.3 dB at 8.2 GHz with a layer thickness of 2.5 mm, and the effective bandwidth is 3.6 GHz (from 12.5 GHz to 16.1 GHz) with a layer thickness of 1.5 mm.

Perturbation training, built upon motor adaptation and learning, has been increasingly used as a fall prevention paradigm in older adults. This training paradigm involves repeated externally-induced perturbations (like slips) to facilitate the error-driven learning of necessary motor skills for preventing falls. It remains unknown if people with multiple sclerosis can adapt to large-scale slip perturbations, which impedes the application of perturbation training in persons with multiple sclerosis. This study explored whether people with multiple sclerosis can adapt to large-scale repeated gait-slips.Thirteen individuals with multiple sclerosis (the mean ± standard deviation of the Patient Determined Disability Steps: 2.27 ± 1.42) were exposed unexpectedly to a block of five repeated standard slips while walking on a treadmill. The outcome (fall or recovery) for each slip, as our primary outcome measure, was determined. A battery of secondary variables, including dynamic gait stability and gait parameters, were also calculated. Both primary and secondary variables were compared across trials.Our participants showed a rapidly reduced slip-fall rate (from 92.3% on the first slip to 30.8% on the fifth, p0.001). They mainly adopted proactive, assisted by reactive, strategies to improve dynamic gait stability, thus reducing the risk of slip-falls. The proactive adjustments, including shortened step, reduced foot landing angle, and flexed knee, shifted the center of mass anteriorly to be closer to the base of support. Such changes in center of mass position improved dynamic gait stability before the slip. Dynamic gait stability after the slip was also improved across trials, as a reactive strategy.With practice, people with multiple sclerosis can adapt to large-scale, high-speed, gait-slips and acquire necessary skills against falls. Such skills primarily involve proactive strategy which is assisted by reactive strategy. The proactive strategy would shift the body's center of mass closer to the base of support, improving dynamic gait stability and reducing falls. Our findings could provide a theoretical foundation for deploying perturbation training to prevent falls in people with multiple sclerosis.

Nowadays, the studying of high-performance microwave absorber with the features of broad bandwidth and strong absorption to address the electromagnetic wave pollution is still a challenge. Thus, based on the careful design of structure and composition, a novel high-performance microwave absorber of hierarchical 1D–2D NiCo2O4 integrating one-dimension nanofibers and two-dimension microsheets is prepared via facile hydrothermal method and subsequent annealing process. The formed NiCo2O4 can be well adjusted under the different annealing temperature. Particularly, varying the annealing temperature from 280 to 600 °C regulates the composition and physicochemical property, further optimizing the microwave absorption performance of hierarchical 1D–2D NiCo2O4. Therefore, when the annealing temperature is 320 °C and the fill ratio in the paraffin is 30%, maximum reflection loss and efficient frequency bandwidth below − 10 dB are − 41.8 dB and 5.35 GHz at a thickness of 2 mm respectively. The superior absorption performance is due to conductive loss, dipole polarization loss, multiple scattering and multiple reflection, which illustrates that hierarchical 1D–2D NiCo2O4 could be regarded as a strong-loss, broadband, and lightweight microwave absorber.

Graphene oxide/carbon nanofibers hierarchical structures have been successfully synthesized through a modified Hummers method. Owing to the harsh chemical exfoliation and oxidation, graphene oxide (GO) appears on the outer walls of carbon nanofibers (CNFs) with the preservation of the 3D fibrous network. By adjusting the oxidation time, the obtained sample exhibited excellent electromagnetic (EM) attenuation performance with a maximum reflection loss of −49.82 dB at a thickness of 1.5 mm. Meanwhile, an effective bandwidth of 2.48 GHz was also investigated. The superior EM absorbing performance of GO/CNFs is ascribed to the hierarchical structure. While the inner carbon skeleton endows the material with desirable conductive network, GO exhibits a larger surface area with abundant functional groups and defects that give rise to multiple polarizations and relaxation processes. Moreover, the resistance-capacitance coupled circuits formed in the GO/CNFs network are beneficial for dissipating the incident waves. Prospectively, the synthetic strategy applied in this research can be extended to assemble GO on carbonaceous materials to fabricate novel microwave absorbers.

Nanoporous carbon (NPC) composites embedded with magnetic nanoparticles have been widely studied for applications in microwave absorption. Herein, highly porous rambutan-like carbon composites decorated with controllable carbon nanotubes (CNTs) and Co nanoparticles were synthesized through a thermal decomposition of Co-doped zeolitic imidazolate frameworks-8 (ZIF-8) under different temperatures. The MOF-derived carbon nanocomposites with the cobalt content accounting for 30% of the total mass of cobalt and zinc, carbonized at 700 °C, exhibited excellent microwave absorption property of −30.2 dB. Characterizations exhibit that the in-situ generated Co nanoparticles are uniformly embedded into NPC matrix, which are surrounded by highly graphitized CNTs. The research presents a facile and promising route for rapid mass production of metal-doped NPC/CNTs composites for high-efficiency microwave absorption.

Prostate cancer (PCa) screening using serum prostate-specific antigen (PSA) testing has caused unnecessary biopsies and overdiagnosis owing to its low accuracy and reliability. Therefore, there is an increased interest in identifying better PCa biomarkers. Studies showed that trained dogs can discriminate patients with PCa from unaffected men by sniffing urine. We hypothesized that urinary volatile organic compounds (VOCs) may be the source of that odor and could be used to develop urinary VOC PCa diagnosis models.Urine samples from 55 and 53 biopsy proven PCa-positive and -negative patients respectively were initially obtained for diagnostic model development. Urinary metabolites were analyzed by gas chromatography-mass spectrometry. A PCa diagnosis model was developed and validated using innovative statistical machine-learning techniques. A second set of samples (53 PCa-positive and 22 PCa-negative patients) were used to evaluate the previously developed PCa diagnosis model.The analysis resulted in 254 and 282 VOCs for their significant association (P .05) with either PCa-positive or -negative samples respectively. Regularized logistic regression analysis and the Firth method were then applied to predict PCa prevalence, resulting in a final model that contains 11 VOCs. Under cross-validation, the area under the receiver operating characteristic curve (AUC) for the final model was 0.92 (sensitivity, 0.96; specificity, 0.80). Further evaluation of the developed model using a testing cohort yielded an AUC of 0.86. As a comparison, the PSA-based diagnosis model only rendered an AUC of 0.54.The study describes the development of a urinary VOC-based model for PCa detection.

High efficient microwave absorption materials are in emergent demand for civil and military application, especially these with light weight and broad absorption bandwidth. In this work, lightweight microwave absorbers consisting of hollow nickel nanoparticles modified reduced graphene oxide (GHN) and epoxy matrix have been successfully prepared via chemical etching method and solution blending process. SEM and TEM images showed that hollow Ni nanospheres are uniformly anchored on the surface of graphene sheets. The introduction of magnetic Ni nanoparticles into dielectric graphene improved integral properties, not only reducing the density but also enhancing microwave absorption capacity. Compared with single hollow Ni samples or graphene samples, GHN/epoxy samples exhibited extraordinary performance originating from the specific structure and multiple loss mechanism. A delta-function and microwave attenuation constant were adopted to quantitatively evaluating the impedance matching condition and microwave energy consumption ability. For GHN-10 samples, optimal reflection loss (RL) could reach up to −33.1 dB with a matching thickness of 4.9 mm. As the coating thickness decreased to 2 mm, the corresponding RL still remained an acceptable numerical value of −23.8 dB and the effective absorption bandwidth extended to about 6.5 GHz (11.5–18 GHz), covering the whole Ku band. The as-synthesized high-performance microwave absorbers would pave a new and promising way to obtain lightweight, broad-band and strong microwave absorption materials.

A 3D structured RGO–AgNWs/EP composite was prepared which composed of 1D silver nanowires and 2D reduced graphene oxide (RGO) sheets. It was found that the electromagnetic wave absorption ability of pure RGO in the matrix was constrained by the agglomeration and defective conductive network. The results show that the addition of silver nanowires significantly enhanced the complex effective permittivity of the composites. Importantly, the absorbing properties can be controlled by the amount of silver nanowires interspersed between the layers of RGO. Besides, a representative sample with only 1% graphene sheets and 15% silver nanowires exhibited a prominent performance whose minimum peak value was up to − 33.2 dB at 11.5 GHz and the corresponding bandwidth was 3.3 GHz with a layer of 1.8 mm. Therefore, the 3D structured RGO–AgNWs assembly has a bright prospect in lightweight and high-performance microwave absorbers.

Double-shell hollow conductive poly(acrylonitrile) microspheres@polyaniline@Ag (PANS@PANI@Ag) was synthesized by a facile two-step method. Polyaniline-coated poly(acrylonitrile) microspheres (PANS@PANI) prepared by in situ polymerization exhibited a porous, corrugated and compact conductive network, making for the formation and attachment of Ag nanoparticles. Incorporating these hollow conductive spheres and reduced graphene oxide (RGO) into epoxy resin, a lightweight microwave absorber was brought out. The chemical composition, micro-structure surface morphology and electromagnetic properties were thoroughly characterized and analyzed. The calculated results showed that the optimal reflection loss (RL) was − 44.9 dB at 9.16 GHz with a constitution of 1 wt% dielectric RGO and 1 wt% conductive PANS@PANI@Ag, and the corresponding effective bandwidth was about 2 GHz. However, the microwave absorption capacity gradually reduced with the raise of PANS@PANI@Ag content, derived from the high conductivity leading to more microwave reflection. As the PANS@PANI@Ag content increased to 5 wt%, the minimum RL was − 14.7 dB and still remained an effective absorption performance with a lower density of 0.47–0.53 g/cm3. Therefore, the as-obtained composites paved a new route for lightweight and strong absorption microwave absorbers in commercial and military application.

To solve the phenomenon of electromagnetic wave radiation and interference, the high-performance microwave absorption materials with strong absorption and wide bandwidth are studied increasingly. Herein, a novel microwave absorption material of graphite nanosheets/core–shell Fe3O4@ppy hybrids (GNFP) is fabricated by facile processes. Fe3O4 nanospheres as chemical template start in the polymerization of pyrrole monomer to form the core–shell Fe3O4@ppy (FP) further placed on the surface of the treated graphite nanosheets (GNS) by 3-aminopropyltriethoxysilane (KH-550). The maximum reflectivity of GNFP hybrids is −49.3 dB at 9.92 GHz, and the bandwidth below −10 dB is 4.08 GHz (12.47–16.55 GHz) with layer thickness of 1.5 mm, which is due to great impedance matching, synergistic effect and multiple reflections. Thus, GNFP composites could be considered as a promising microwave absorber.

Objectives: To examine the concurrent use of self-report questionnaires and hormonal biomarkers, specifically levels of testosterone and cortisol, along with demographic variables and corrected age (CA) in the assessment of mental health and healthy behaviors among mothers of very-low-birthweight (VLBW, BW < 1,500 g) infants at five time points over 2 years post birth. Method: Data on 40 mothers from a neonatal intensive care unit of a tertiary medical center in the southeast United States were collected from the medical record, standard questionnaires for the mother (depressive symptoms, perceived stress, anxiety, mental health status, parenting stress, and healthy lifestyle behaviors), and biochemical measurement of maternal testosterone and cortisol using enzyme immunoassay at birth, 40 weeks’ postmenstrual age, and 6, 12, and 24 months CA. Results: Maternal self-report of mental health improved from birth to 6 or 12 months then worsened at 24 months. Mixed linear models showed that mothers with higher testosterone levels had more depressive symptoms and smoked more, whereas mothers with higher cortisol levels had healthier behaviors and exercised more. Testosterone levels were negatively correlated with cortisol levels. Marital status, education, and health insurance were the most predictive demographic variables for the levels of hormonal biomarkers, mental health, and healthy behaviors. Conclusions: The use of self-report and biochemical measurement was effective in assessing maternal mental health and healthy behaviors over 2 years post birth, when mothers of VLBW infants tend to experience more mental health problems and parenting difficulties than mothers of normal-BW full-term infants.

Background Mobility impairment is common in people with multiple sclerosis (MS). Gait speed has shown strong correlations with other mobility measures in MS. The purpose of this study was to assess the relative importance of a battery of factors in determining gait speed among people with MS. Methods Thirty-one individuals with MS (the mean (standard deviation) of the Patient Determined Disability Steps: 3.68(1.70)) participated in this cross-sectional observational study. Their gait speed was assessed using the Timed-25-Foot Walking test. Six factors which could slow gait speed in MS, including the strength capacity at knee joints, functional mobility, body balance, dorsiflexion range of motion of ankle joints, bilateral foot cutaneous sensation level, and the fear of falling, were also assessed. Multiple regression and relative weight analysis were used to identify the relative importance of each factor in explaining the gait speed variation. Results All six factors together accounted for about 86% of the observed variation in gait speed; each explaining a statistically significant amount. The most important factor was the strength measurement (relative weight = 0.321) which accounted for 37.2% of the explained variation in gait speed. Conclusion : Muscle strength, particularly the knee joint strength capacity, could be a principal factor determining gait speed in people with mild to moderate MS. Other factors also significantly affect gait speed in this population. The findings from this study could provide guidance in terms of prioritizing actions to improve gait speed in people with MS.