Probabilistic Estimation of Cadence and Walking Speed From Floor Vibrations.

OBJECTIVE: This research aims to extract human gait parameters from floor vibrations. The proposed approach provides an innovative methodology on occupant activity, contributing to a broader understanding of how human movements interact within their built environment. METHODS AND PROCEDURES: A multilevel probabilistic model was developed to estimate cadence and walking speed through the analysis of floor vibrations induced by walking. The model addresses challenges related to missing or incomplete information in the floor acceleration signals. Following the Bayesian Analysis Reporting Guidelines (BARG) for reproducibility, the model was evaluated through twenty-seven walking experiments, capturing floor vibration and data from Ambulatory Parkinson's Disease Monitoring (APDM) wearable sensors. The model was tested in a real-time implementation where ten individuals were recorded walking at their own selected pace. RESULTS: Using a rigorous combined decision criteria of 95% high posterior density (HPD) and the Range of Practical Equivalence (ROPE) following BARG, the results demonstrate satisfactory alignment between estimations and target values for practical purposes. Notably, with over 90% of the 95% HPD falling within the region of practical equivalence, there is a solid basis for accepting the estimations as probabilistically aligned with the estimations using the APDM sensors and video recordings. CONCLUSION: This research validates the probabilistic multilevel model in estimating cadence and walking speed by analyzing floor vibrations, demonstrating its satisfactory comparability with established technologies such as APDM sensors and video recordings. The close alignment between the estimations and target values emphasizes the approach's efficacy. The proposed model effectively tackles prevalent challenges associated with missing or incomplete data in real-world scenarios, enhancing the accuracy of gait parameter estimations derived from floor vibrations. CLINICAL IMPACT: Extracting gait parameters from floor vibrations could provide a non-intrusive and continuous means of monitoring an individual's gait, offering valuable insights into mobility and potential indicators of neurological conditions. The implications of this research extend to the development of advanced gait analysis tools, offering new perspectives on assessing and understanding walking patterns for improved diagnostics and personalized healthcare.Clinical and Translational Impact Statement: This manuscript introduces an innovative approach for unattended gait assessments with potentially significant implications for clinical decision-making. By utilizing floor vibrations to estimate cadence and walking speed, the technology can provide clinicians with valuable insights into their patients' mobility and functional abilities in real-life settings. The strategic installation of accelerometers beneath the flooring of homes or care facilities allows for uninterrupted daily activities during these assessments, reducing the reliance on specialized clinical environments. This technology enables continuous monitoring of gait patterns over time and has the potential for integration into healthcare platforms. Such integration can enhance remote monitoring, leading to timely interventions and personalized care plans, ultimately improving clinical outcomes. The probabilistic nature of our model enables uncertainty quantification in the estimated parameters, providing clinicians with a nuanced understanding of data reliability.

Effectiveness of energy absorbing floors in reducing hip fractures risk among elderly women during sideways falls.

Falls among the elderly cause a huge number of hip fractures worldwide. Energy absorbing floors (EAFs) represent a promising strategy to decrease impact force and hip fracture risk during falls. Femoral neck force is an effective predictor of hip injury. However, the biomechanical effectiveness of EAFs in terms of mitigating femoral neck force remains largely unknown. To address this, a whole-body computational model representing a small-size elderly woman with a biofidelic representation of the soft tissue near the hip region was employed in this study, to measure the attenuation in femoral neck force provided by four commercially available EAFs (Igelkott, Kradal, SmartCells, and OmniSports). The body was positioned with the highest hip force with a -10∘ trunk angle and +10∘ anterior pelvis rotation. At a pelvis impact velocity of 3 m/s, the peak force attenuation provided by four EAFs ranged from 5% to 19%. The risk of hip fractures also demonstrates a similar attenuation range. The results also exhibited that floors had more energy transferred to their internal energy demonstrated greater force attenuation during sideways falls. By comparing the biomechanical effectiveness of existing EAFs, these results can improve the floor design that offers better protection performance in high-fall-risk environments for the elderly.

The association between flooring materials and childhood asthma: A prospective birth cohort in the Japan Environment and Children's Study.

BACKGROUND: Childhood asthma is known to be affected by a range of factors, including conditions in the indoor environment. While flooring material influences indoor air conditions, the potential association between flooring materials and childhood asthma remains poorly understood in Japan. OBJECTIVE: The present study aims to assess the association between childhood asthma incidence and the primary flooring material with the ongoing prospective nationwide birth cohort data of the Japan Environment and Children's Study (JECS). METHODS: The JECS gathered data on mothers and children through 15 Regional Centres across Japan. The present study assessed flooring materials used in the home and asthma incidence at age four among children born between 2011 and 2014. We implemented logistic regressions, setting asthma incidence among the children as the outcome and home floor type as the exposure. Additional analyses were conducted, stratifying the home's age as a proxy for tatami age, to assess whether the potential effect of tatami flooring on asthma risk is influenced by its age. RESULTS: The present study included total of 75,629 infants. For tatami flooring, the main multivariable regression and additional sub-group regression for homes over ten years old produced odds ratios of 1.09; 95% Confidence Interval (CI) [1.01-1.17] and 1.10; 95% CI [1.00-1.21] compared with flooring, respectively. CONCLUSION: These results imply that exposure to tatami flooring, particularly in older homes, may be associated with childhood asthma incidence. Moreover, our study highlights the importance of evaluating the relationship between regional and cultural differences between asthma and flooring materials.

Influence of floor inclination on handle push and pull forces production of the upper limb.

Floor inclination can alter hand force production, and lower limb kinetics, affecting control operations, and threatening operator safety in various domains, such as aviation, naval, construction industry, or agriculture. This study investigates the effects of different floor inclinations, on handle push or pull force production. Participants performed maximal isometric contraction tasks requiring to exert a maximal voluntary force either by pulling or pushing a handle, at different floor inclinations from -30° to +30° about the transverse and longitudinal axes. Maximal hand force and Ground Reaction Forces about both feet were recorded. The results revealed non-equivalent variations in hand and feet responses as a function of inclination angle. Specifically, there was a significant reduction in handle push-pull force production, up to 70% (p < 0.001) for extreme inclinations, around both axes. This study provides critical data for design engineers, highlighting the challenge of production forces at steep angles.

Evaluation of the microbial wet-vacuum system (M-Vac®) for DNA sampling from rough, porous substrates, and its compatibility with fully automated platforms.

DNA retrieval methods traditionally used during forensic evidence recovery including swabbing and tape lifting, can have limited effectiveness when used on porous, rough substrates such as bricks and carpet. This is possibly due to the DNA material being dispersed and unreachable for surface sampling techniques. In this evaluation we investigated the effectiveness of the Microbial Wet-Vacuum System (M-Vac®; M-Vac® Systems, Inc., Sandy, UT), as it has been reported to retrieve greater amounts of DNA material from challenging exhibits. A four-stage evaluation was conducted, starting with seeding carpet and brick substrates with a known donor's saliva in two dilutions and comparing the DNA recovery of tape lifting, swabbing, and the M-Vac®. A victim struggle scenario on carpet was then mimicked to compare trace DNA recovery by each method. Two mock scenarios were also conducted; a shirt was submerged in a creek bed for a period of five days to sample for the wearer's DNA, and a car boot was sampled to assess the possibility of recovering a victim's DNA amongst background DNA from the usual car occupants. Finally, the compatibility of the M-Vac® sampling process was optimised for the fully automated DNA lysis and extraction platforms used in the NSW (Australia) jurisdiction by comparing filter subsampling methods. The results from the study were mixed. For bricks, none of the collection methods were effective in retrieving DNA. On carpet, the M-Vac® retrieved the greatest quantities of DNA from the saliva-seeded samples, however, tape lifts outperformed all methods for 'touch' DNA recovery. The M-Vac® retrieved the greatest amount of DNA from the t-shirt recovered from a creek bed as it was able to retrieve the embedded DNA. The final mock case car boot scenario resulted in greater victim DNA recovery from tape lifts, with the M-Vac® more likely to recover mixtures too weak and/or complex to be interpreted. Finally, operational considerations regarding the compatibility of the M-Vac® system with fully automated DNA lysis and extraction are discussed. Considering the substantial time and cost to deploy the M-Vac®, it is recommended to be utilised in casework only after swabbing and tape lifting methods have failed to yield sufficient DNA material, where the substrate properties would likely benefit from the M-Vac's® niche capabilities for retrieving embedded DNA, and low levels of background DNA may be anticipated.

Acinetobacter in fresh faecal samples is related to sperm motility: A case report in Piétrain boars housed on different deep-litter bedding materials.

The swine gastrointestinal tract contains a great variety of microbes, forming a complex and dynamic ecosystem. Various internal and external factors (e.g. age, breed and diet) may influence its composition. This study aimed to investigate the gut microbial diversity of German Piétrain boars housed on different deep-litter bedding materials (regional wood shavings, linen, hemp, spelt husks, and wood shavings) via 16S-rDNA sequencing. Additionally, short-chain fatty acids were analysed using gas chromatography. Fresh faecal samples (n = 80) from 40 Piétrain boars were collected twice during the trial. Although it can be assumed that boars ingest bedding orally, no differences in the microbiome composition could be found. The main phyla were Firmicutes and Bacteroides. Acinetobacter was identified as a biomarker for sperm quality differences (total sperm motility) in breeding boars.

Performance and economic efficiency of laying hens in response to adding zeolite to feed and litter.

This study investigated the effect of different levels of zeolite in laying hen (Silver Montazah) diet and litter on productive performance, egg quality criteria, and economics during the second stage of production (40-56 wk of age). An experiment with a 3 × 4 factorial design was performed to study the effects of four levels of zeolite (0, 10, 15, and 20 g/kg feed) in the diet and three levels of zeolite (0, 1.5, and 2 kg/m2) in the litter. Adding zeolite to diet and litter significantly improved final BW and BW change, egg number, egg weight, egg mass, laying rate, feed consumption (FC), and feed conversion ratio (FCR), as well as egg quality criteria when compared to the unsupplemented group. Additionally, adding zeolite at a level of 2 kg /m2 litter and 20 g/kg diet achieved the greatest enhancement in productive performance features. Therefore, it can be suggested that the greatest results were obtained in laying farms when zeolite was added as a litter addition and as a supplement to feed.

Efficacy of three EPA-registered antimicrobials and steam against two human norovirus surrogates on nylon carpets with two backing types.

Carpet cleaning guidelines currently do not include the use of an antimicrobial, except after a bodily fluid event. To address this gap, we compared the efficacy of three antimicrobials-two hydrogen peroxide-based (H2O2) products (A and B) and one chlorine-based product (C)-and a steam treatment against two norovirus surrogates, specifically feline calicivirus (FCV) and Tulane virus (TuV). These tests were performed on nylon carpets with either water-permeable or waterproof backing types. The effect of repeated antimicrobial use on carpet properties was also evaluated. For a carpet with water-permeable backing, products A, B, and C achieved a 0.8, 3.1, and 0.9 log10 PFU/coupon reduction of FCV and 0.3, 2.5, and 0.4 log10 TCID50/coupon reduction of TuV, respectively, following a 30 min contact time. For carpet with waterproof backing, only product B achieved a 5.0 log10 PFU/coupon reduction of FCV and >3.0 log10 TCID50/coupon reduction of TuV, whereas products A and C achieved a 2.4 and 1.6 log10 PFU/coupon reduction of FCV and a 1.2 and 1.2 log10 TCID50/coupon reduction of TuV, respectively. Steam treatment achieved a ≥ 5.2 log10 PFU/coupon reduction of FCV and a > 3.2 log10 TCID50/coupon reduction of TuV in 15 seconds on the carpet with both backing types. The repeated use of products A and B decreased the tensile strength of the carpet backing, while use of product B resulted in cracks on carpet fibers. Overall, steam treatment for 15 seconds was efficacious on both carpet types, but only product B achieved efficacy after a 30-minute exposure on the carpet with waterproof backing.IMPORTANCECarpets are common in long-term care facilities, despite its potential as a vehicle for transmission of agents associated with healthcare-associated infections, including human norovirus (NoV). Presently, our understanding of carpet disinfection is limited; hence, there are no commercial antimicrobials against norovirus available for use on carpets. Our findings showed that steam treatment, which minimally affected the properties of carpet fibers and backing, was more efficacious against human norovirus surrogates on carpets compared to the three chemical antimicrobials tested. Additionally, the two surrogates were more sensitive to chemical antimicrobials on the carpet with waterproof backing compared to carpets with water-permeable backing. These findings can inform development of antimicrobials for use on carpets contaminated with human norovirus.

Synergistic approaches to elevate indoor air quality: A holistic examination of classroom refinement, air exchange optimization, and flooring material impact.

This research endeavors to elevate indoor air quality within aging school environments by concentrating on refining interior finishing materials and windows. Renovations, encompassing window and floor remodeling in classrooms, aim to mitigate particulate matter (PM) infiltration and enhance air exchange rates. Utilizing SPS30 sensors for the analysis of 0.3-2.5 µm particles, with a focus on their implications for human health, the study evaluated air exchange rates, deposition rates, infiltration rates, and particle generation during classroom activities. Post-renovation results demonstrated a noteworthy decrease in air exchange rates, indicating an enhancement in airtightness. The investigation delves into particle generation with various flooring materials, accentuating the importance of opting for durable and low-particle-generating alternatives. Health risk assessments, considering multiple exposure routes (inhalation, dermal contact, and ingestion), revealed reduced risks post-renovation, particularly for children. To further optimize indoor air quality, the study suggests the implementation of air purification systems. Examination of PM generation during student activities showcased a substantial reduction post-renovation. This study underscores the positive influence of architectural enhancements on indoor air quality while acknowledging the necessity for holistic solutions and continuous research.

Evaluating the impact of gypsum as a novel bedding material on broiler performance, foot pad health, and fear response.

Flue Gas Desulfurization (FGD) gypsum is a byproduct of the coal-fired power plant process commonly used to remove sulfur dioxide emissions from the flue gas. FGD gypsum has numerous industrial, agricultural, and environmental applications. This study aimed to explore a novel approach involving the use of FGD gypsum combined with different litter treatments as bedding for broiler production. It focused on performance metrics, including adjusted feed conversion ratio (AFCR) and average body weight (BW), foot pad dermatitis (FPD), and fear response over 5 consecutive flocks. A total of 1,800 one-day-old Ross 708 chicks were randomly assigned to 24 pens (75 birds/pen), divided into 6 treatment groups (4 pens/treatment), with 5 replications and raised until 42 d old (d). Treatments were gypsum that was decaked (D), rotovated (E), and rotovated then windrowed (F) between flocks. Control treatments using pine shavings were decaked (A), rotovated (B), and windrowed postrotovating (C). AFCR, average BW, and mortality were used as a measure of production. Foot pad dermatitis scores were taken on d42 using a scale of 0 (absence), 1 (mild), and 2 (severe). Response to observer and human approach test were used to measure fear response. Data were analyzed as a 2-way ANOVA (Proc Glimmix) for the main effects of bedding type and litter treatment. Means were identified using Tukey's HSD. No effect of bedding type or litter treatment was found for AFCR, BW, or mortality. FPD scores 2 and 1, were higher with pine shavings than gypsum (P = 0.01 and P = 0.01, respectively). While FPD scores 0 were higher for gypsum than the pine shaving (P = 0.01). No difference in fear response was found among birds raised on any of the gypsum litter treatments and any of the pine shaving litter treatments. Overall, the use of gypsum as bedding results in equivalent production and fear response to pine shavings, while increasing FPD quality when compared to pine shaving.

Effects of water access time and unlimited access to alfalfa straw on litter quality, performance, and behavior of breeder pullets.

Between 3 and 20 wk of age (WOA), the effects of water access time and access to alfalfa during the rearing phase on the litter conditions, performance, and behavior of broiler breeder pullets was studied. A total of 480 female one-day-old chicks (Ross 308) were randomly assigned to 24 floor pens (20 pullets/pen) within a 3 × 2 factorial completely randomized block design. Between 3 and 20 WOA, pullets received water 1) between 07:30 am and 10:30 pm h (3HR), 2) in 2 periods between 07:30 am and 11:00 pm h and between 14:00 pm and 15:30 pm h (5HR), or 3) during the entire light period (8HR). Half of the pens had unlimited access to alfalfa straw (ALF+) or not (ALF-). Higher water use and water-to-feed ratios were observed in the 5HR and 8HR pullets compared to the 3HR pullets (P < 0.001), with no effect observed from unlimited alfalfa. Clear differences in water use throughout the day were observed for the different water strategies. The dry matter (DM) content in the litter was lower, and the litter friability and moisture scores were higher in the 5HR and 8HR than the 3HR pens (P < 0.001), with no differences in fresh feces DM. Alfalfa straw had no effect on litter DM content, fresh feces DM content, litter friability score, or litter moisture score. Feather cover score and feather and footpad contamination score were higher in 5HR and 8HR pullets than in 3HR pullets (P < 0.05), with no differences between the ALF+ and ALF- pullets. The 5HR and 8HR pullets showed increased pecking at alfalfa straw and drinking nipples, along with decreased foraging and perching than the 3HR pullets (P < 0.05). Additionally, ALF+ pullets showed a tendency for less object pecking behavior (P = 0.066) than ALF- pullets. In conclusion, the study demonstrated that extended access to water in breeder pullets increased water use, resulting in inferior litter quality, decreased feather cover, and decreased feather cover and footpad contamination. Moreover, unlimited access to alfalfa straw decreased object pecking behavior.

Microorganism diversity and contamination risk in mosque rosaries and carpets.

BACKGROUND: Inevitably, the floors of mosques are contaminated with microorganisms, and the risk of pathogen transmission is probably high between the many visitors, but the issue has been infrequently studied. OBJECTIVES: Investigate microorganism variety and risk of contamination on commonly used carpets and rosaries (prayer beads). DESIGN: Cross-sectional. SETTINGS: Mosques. METHODS: This study was carried out in three different cities of Turkey in 2023, focusing on mosques located around hospitals. Forty mosques were included in the study and from each mosque 10 samples were collected from various parts of carpets and rosaries. The number of positive culture isolates were identified. MAIN OUTCOME MEASURES: Diversity and distribution of microorganisms isolated from mosque carpets and rosaries; methicillin-resistance rates in Staphylococci. SAMPLE SIZE: 400 samples. RESULTS: Growth was observed in 368 (92%) of 400 samples examined. The microorganisms isolated in the highest number were methicillin-susceptible coagulase negative Staphylococci (MSCoNS) (59.8%), Microcooccus (41%) and diphtheroids (31.3%). The rates of total growth (P=.001), including diphtheroids (P=.018), methicillin-resistant coagulase negative Staphylococci (P=.001), Bacillus spp. (P=.036) and Aspergillus spp. (P=.002) rates were significantly higher in the rosary samples than carpet samples. At mosques in Tokat, a province center, 4 samples were positive for Acinetobacter baumannii, two samples were positive for Pseudomonas aeruginosa and one sample for methicillin-resistant Staphylococcus aureus (MRSA), and these were isolated from rosaries. 0.3% of Staphylococcus isolates were MRSA. CONCLUSION: As there is a high risk of contamination of carpets and prayer beads on the mosque floor with human flora, the use of appropriate hygiene practices is necessary. We also found some emerging bacteria in addition to the normal human flora. LIMITATIONS: Our study was conducted in three provinces. Further studies might cover a wider geography.

Ubiquitous Gait Analysis through Footstep-Induced Floor Vibrations.

Quantitative analysis of human gait is critical for the early discovery, progressive tracking, and rehabilitation of neurological and musculoskeletal disorders, such as Parkinson's disease, stroke, and cerebral palsy. Gait analysis typically involves estimating gait characteristics, such as spatiotemporal gait parameters and gait health indicators (e.g., step time, length, symmetry, and balance). Traditional methods of gait analysis involve the use of cameras, wearables, and force plates but are limited in operational requirements when applied in daily life, such as direct line-of-sight, carrying devices, and dense deployment. This paper introduces a novel approach for gait analysis by passively sensing floor vibrations generated by human footsteps using vibration sensors mounted on the floor surface. Our approach is low-cost, non-intrusive, and perceived as privacy-friendly, making it suitable for continuous gait health monitoring in daily life. Our algorithm estimates various gait parameters that are used as standard metrics in medical practices, including temporal parameters (step time, stride time, stance time, swing time, double-support time, and single-support time), spatial parameters (step length, width, angle, and stride length), and extracts gait health indicators (cadence/walking speed, left-right symmetry, gait balance, and initial contact types). The main challenge we addressed in this paper is the effect of different floor types on the resultant vibrations. We develop floor-adaptive algorithms to extract features that are generalizable to various practical settings, including homes, hospitals, and eldercare facilities. We evaluate our approach through real-world walking experiments with 20 adults with 12,231 labeled gait cycles across concrete and wooden floors. Our results show 90.5% (RMSE 0.08s), 71.3% (RMSE 0.38m), and 92.3% (RMSPE 7.7%) accuracy in estimating temporal, spatial parameters, and gait health indicators, respectively.

Effects of surface-attached durations, nutrients, and relative humidity on the resuspension of bacteria during human walking.

Resuspension caused by human walking activities is an important source of indoor bioaerosols and has been associated with health effects such as allergies and asthma. However, it is unknown whether inhalation of resuspended bioaerosols is an important exposure pathway for airborne infection. Also, crucial factors influencing the resuspension of settled microbes have not been quantified. In this study, we experimentally investigated the resuspension of culturable bacteria from human-stepping on polyvinyl chloride (PVC) flooring under different conditions. We determined the bacterial resuspension emission factor (ER), a normalized resuspension parameter for the ratio of resuspended mass in the air to the mass of settled particles, for two common bacteria, Escherichia coli and Salmonella enterica. The investigation involved varying factors such as microbial surface-attached durations (0, 1, 2, and 3 days), the absence or presence of nutrients on flooring surfaces, and changes in relative humidity (RH) (35%, 65%, and 85%). The results showed that, in the absence of nutrients, the highest ER values for E. coli and S. enterica were 3.8 × 10-5 ± 5.2 × 10-6 and 5.3 × 10-5 ± 6.0 × 10-6, respectively, associated with surface-attached duration of 0 days. As the surface-attached duration increased from 0 to 3 days, ER values decreased by 92% and 84% for E. coli and S. enterica, respectively. In addition, we observed that ER values decreased with the increasing RH, which is consistent with particle adhesion theory. This research offers valuable insights into microbial resuspension during human walking activities and holds the potential for assisting in the assessment and estimation of risks related to human exposure to bioaerosols.

A scoring system for grading corkscrew claws in dairy cattle.

Corkscrew claw (CC) in dairy cattle is increasingly reported in dairy herds. CC is a progressive deformity of the claw capsule with uncertain aetiology and pathogenesis. Genetics and specific environmental factors are suspected of contributing to the development of this irreversible condition. CC has been found in lame cows; however, the cause and effect has not been established. To perform analysis of risk factors, treatment and pathogenesis, a definition of severity scores is called for. The aim of this study was to measure and analyse CC characteristics from photos of cows' feet to describe and evaluate a scoring system for CC. Width of the visible part of the axial wall, degree of contact between the toe and the floor and angle of the distal part of the abaxial wall as a proxy for the deviation of the abaxial wall was measured from 393 pictures of CC. Based on the measurements on the claws, the parameter "width of the axial wall" was chosen to define the scores. The parameter was divided into three intervals to define either mild CC 0.3-2.0 cm, moderate CC 2.1-3.5 cm or severe CC>3.5 cm and correlation between the parameters; level of contact between the toe and the floor and the angle of the distal abaxial wall was evaluated. There was a significant positive linear correlation between width of the axial wall and angle of the distal part of the abaxial wall (r=0.91), the wider the axial wall, the more the abaxial wall deviated in the distal part. As the width of the axial wall increased the toe increasingly lost contact with the floor, this association was significant for mild CC and moderate CC but not for severe CC. The Interobserver agreement of the CC Scoring system was tested by 30 claw trimmers each scoring 32 cadaver feet and by 2 trained observers on 28 photos of feet using Cohen´s weighted kappa and showed substantial to almost perfect agreement between untrained and trained observers, respectively.

Potential exposure of adults and children to particles from resuspended nano-enabled consumer sprays.

The increasing application of nanotechnology has resulted in a growing number of nano-enabled consumer products, and they could be important contributors to indoor particulate matter, with potential adverse health effects. This study investigated the exposure of adults and children to the released and resuspended manufactured particles from seven nano-enabled consumer sprays. Sedimentation and resuspension of released particles were investigated in a newly constructed 2.8 × 1.6 × 2.4 m3 chamber. The resuspension of deposited particles was investigated as a function of product type, flooring material (e.g., carpet and vinyl), resuspension force (e.g., walking by an adult and motion of a robotic sampler that simulated a child), and measurement height. The concentration of released and resuspended particles in the air was determined using Button Aerosol Samplers (SKC Inc.) with 25-mm 2 µm-pore PTFE filters. Samplers were positioned in the experimenter's breathing zone (e.g., 1.5 m for adults and 0.3 m for a child-simulating robot) and at fixed stations of 0.3 m and 1.1 m heights. Resuspended particle mass concentrations ranged from 28 to 905 µg/m3, and the resuspension rates of deposited spray particles for the same variable combinations varied from 10-4 to 10-1 h-1, depending on product type, flooring material, sampling height, and resuspension force. Particle resuspension rates from carpet were up to 320 % higher than resuspension rates from vinyl flooring, resuspension rates measured at 0.3 m were up to 195 % higher than the rates measured with a 1.1 m stationary sampler, and resuspension rates due to a walking adult were up to 243 % higher than resuspension rates caused to a moving robot that simulated a child. Overall, these data on the resuspension of particles from nano-enabled consumer sprays could help us understand the resulting exposures and support future studies on human exposure reduction.

Effects of Salvinia as a broiler litter material on growth performance, behavior, welfare parameters, litter characters, and ammonia emission.

The type of litter material has direct impacts on production, behavioral, and welfare parameters of broilers. The price of conventionally-used litter materials is increasing. Salvinia molesta is a fast-growing aquatic plant which has become an environmental issue in some areas. This study assessed the suitability of air-dried Salvinia plants (SAL) as an alternate litter material to paddy husk (PH). Resulting in a completely randomized experiment, a total of 240 broilers was raised in 12 floor-pens each provided with either PH or SAL as litter materials, from 11 to 36 d. Scan sampling technique was employed to record the birds' engagement in 15 predetermined behaviors. Foot pad dermatitis (FPD), hock burn damage (HBD) and plumage cleanliness (PC) were assessed using Welfare Quality Scoring System. Litter samples were analyzed for pH, dry matter%, water holding capacity, porosity, N%, tapped-density and ammonia emission rate. The litter material had no significant effect (P > 0.05) on mortality, growth performance parameters, dressing % and visceral organ weight. The scores for FPD and PC were unaffected by the litter materials. SAL litter reported significantly lower (P < 0.05) HBD scores. The percentages of birds engaged in eating and wing flapping behaviors were significantly lower on SAL. Litter type had no significant influence on the color, aroma, flavor, texture and overall acceptability of breast meat. Air-dried Salvinia plants reported acidic pH. SAL litter gave a significantly higher tapped-density. Ammonia emission rate of SAL litter was significantly lower than that of PH. However, the final litter N content was higher for PH (3.7%) than SAL (3.2%). The study proposes air-dried Salvinia plants as a litter material for broilers since it gives growth performance comparable to PH with reduced hock burn damage incidences. Effects of SAL on behavior and the fertilizer value of the spent litter are to be studied further.

Machine learning prediction of footwear slip resistance on glycerol-contaminated surfaces: A pilot study.

Slippery surfaces due to oil spills pose a significant risk in various environments, including industrial workplaces, kitchens, garages, and outdoor areas. These situations can lead to accidents and falls, resulting in injuries that range from minor bruises to severe fractures or head trauma. To mitigate such risks, the use of slip resistant footwear plays a crucial role. In this study, we aimed to develop an Artificial Intelligence model capable of classifying footwear as having either high or low slip resistance based on the geometric characteristics and material parameters of their outsoles. Our model was trained on a unique dataset comprising images of 37 indoor work footwear outsoles made of rubber. To evaluate the slip resistant property of the footwear, all samples were tested using a cart-type friction measurement device, and the static and dynamic Coefficient of Frictions (COFs) of each outsole was determined on a glycerol-contaminated surface. Machine learning techniques were implemented, and a classification model was developed to determine high and low slip resistant footwear. Among the various models evaluated, the Support Vector Classifier (SVC) obtained the best results. This model achieved an accuracy of 0.68 ± 0.15 and an F1-score of 0.68 ± 0.20. Our results indicate that the proposed model effectively yet modestly identified outsoles with high and low slip resistance. This model is the first step in developing a model that footwear manufacturers can utilize to enhance product quality and reduce slip and fall incidents.

Transmission of fore-and-aft floor vibration to the spine and head of standing people.

Sixteen standing male participants were subjected to fore-and-aft sinusoidal vibration with peak magnitude and frequency in the range 0.44-4.431 ms-2 and 2-6 Hz, respectively. The fore-and-aft, lateral and vertical transmissibilities to the first dorsal vertebra (T1), eighth dorsal vertebra (T8), twelfth dorsal vertebra (T12), fourth lumbar vertebra (L4) and head were measured. Large inter-participant variability was observed in the transmissibilities at all locations. Nevertheless, peaks in the range 3-4.5 Hz were identified at all locations, implying a whole-body resonance in this frequency range. The response was found dominant in the mid-sagittal plane as the lateral transmissibility showed low values. Below 4.5 Hz, the fore-and-aft transmissibility increased with moving from caudal to cranial locations of the upper body. However, at higher frequencies, the opposite trend was observed. The results can be used for developing models that may help understand how vibration affects health and comfort.