A Multi-Purpose Realistic Haze Benchmark With Quantifiable Haze Levels and Ground Truth.

Imagery collected from outdoor visual environments is often degraded due to the presence of dense smoke or haze. A key challenge for research in scene understanding in these degraded visual environments (DVE) is the lack of representative benchmark datasets. These datasets are required to evaluate state-of-the-art object recognition and other computer vision algorithms in degraded settings. In this paper, we address some of these limitations by introducing the first realistic haze image benchmark, from both aerial and ground view, with paired haze-free images, and in-situ haze density measurements. This dataset was produced in a controlled environment with professional smoke generating machines that covered the entire scene, and consists of images captured from the perspective of both an unmanned aerial vehicle (UAV) and an unmanned ground vehicle (UGV). We also evaluate a set of representative state-of-the-art dehazing approaches as well as object detectors on the dataset. The full dataset presented in this paper, including the ground truth object classification bounding boxes and haze density measurements, is provided for the community to evaluate their algorithms at: https://a2i2-archangel.vision. A subset of this dataset has been used for the "Object Detection in Haze" Track of CVPR UG2 2022 challenge at https://cvpr2022.ug2challenge.org/track1.html.

Retention strategies and predictors of attrition in an urban pediatric asthma study.

BACKGROUND: The Urban Environment and Childhood Asthma (URECA) study is a multicenter prospective birth cohort study designed to examine factors related to the development of childhood asthma and allergies in an inner-city population. The retention of these participants has been challenging due to high mobility, inconsistent phone service, custody issues, and stressful life situations. PURPOSE: In this article, we describe the specific retention challenges we encountered during the first 2 years of follow-up in URECA and the strategies we utilized to address them. We also examine how selected maternal characteristics and other factors are related to retention and missed study visits. METHODS: Strategies implemented to engage participants included: collecting updated and alternative contact information, after-hours phone calls to participants, culturally competent staff, flexible study event scheduling, clinic visit transportation, quarterly newsletters, retention events, drop-in home visits, and cell phone reimbursements. An internally developed web-based data management system enabled close monitoring by site teams and the coordinating center. The rate of deactivations was calculated using survival analysis. Characteristics of active and deactivated participants were compared using the chi-squared test with a Cochran-Mantel - Haenszel adjustment for study site. The proportion of missed visits of the total expected in the first 2 years was calculated and compared by family characteristics using an ANOVA model or a trend test controlling for study site. All analyses were performed using SAS version 9.1 (Cary, NC). RESULTS: The 2-year retention rate was 89%. Participation in the first study event predicted subsequent engagement in study activities. Mothers who did not complete the first visit were more likely to miss future events (46.1% vs. 8.9%, p<0.0001) and to be deactivated (38.5% vs. 4.5%, p<0.0001). Mothers under 18 years of age were more likely to leave the study compared to older mothers (22.7% vs. 10.1%, p = 0.02). Also, mothers who were married missed fewer events than those not married (8.8% vs. 15.6%, p = 0.01). In addition, deactivations were more common when the child had entered daycare by 3 months of age (10.9% vs. 3.6%, p = 0.05). LIMITATIONS: The URECA population is predominantly minority, thus our findings might not be generalizable to other populations. Furthermore, we may not be able to observe the effects that might exist in a more diverse population. For example, 86% of the mothers are unmarried, making it difficult to reliably examine the effect of marital status. CONCLUSION: In research, successfully engaging and retaining participants is essential for achieving the study objectives. Identifying factors related to missed visits and deactivations are the initial step in recognizing the potential at-risk participants and can enable the design of targeted strategies to retain participants.

Decreasing Catheter-Associated Urinary Tract Infections in the Neurological Intensive Care Unit: One Unit's Success.

BACKGROUND: Catheter-associated urinary tract infections are preventable adverse outcomes that increase hospital morbidity, mortality, and costs. These infections are particularly prevalent in intensive care units. OBJECTIVES: To describe the success of an 18-bed neurological intensive care unit in using several nurse-implemented strategies that reduced the number of catheter-associated urinary tract infections. METHODS: A prospective, interventional design with application of evidence-based practices to reduce catheter-associated urinary tract infections was used. RESULTS: Before implementation of the strategies, 40 catheter-associated urinary tract infections were reported for 2012 and 38 for 2013. The standardized infection ratio was 2.04 for 2012 (95% CI, 1.456-2.775) and 2.34 (95% CI, 1.522-3.312) for 2013. After implementation of the strategies, significantly fewer catheter-associated urinary tract infections were reported. In 2014, a total of 15 infections were reported, and the standardized infection ratio was less than 1.0 (95% CI, 0.685-1.900). CONCLUSIONS: Application of current evidence-based practices resulted in a substantial decrease in the number of catheter-associated urinary tract infections and a lower standardized infection ratio. These findings support current recommendations for "bundling" to maximize outcomes.

Delayed tuberculosis diagnosis and costs of contact investigations for hospital exposure: New York City, 2010-2014.

BACKGROUND: A delayed diagnosis of tuberculosis (TB) in the hospital may lead to nosocomial exposure, placing employees and other patients at risk. A lack of prompt infection control measures for suspected cases at the time of admission may require complicated and expensive contact investigations. The purpose of this study was to estimate the person-hour costs required by infection control staff to investigate a single hospital-based TB exposure. METHODS: Electronic data were extracted from 2 tertiary hospitals and 1 community hospital in a large health care system in metropolitan New York City to identify pulmonary TB cases unsuspected at admission. All cases were reviewed by infection prevention and control (IPC) staff to identify exposures. RESULTS: From 2010-2014, 34 pulmonary TB cases which necessitated a contact investigation were identified. IPC staff calculated an average of 15-20 hours of work per exposure plus 30 minutes of follow-up for each exposed staff member. For exposures, time from admission to isolation averaged 3.3 days, with a mean of 41 staff exposed per patient and an approximate resource usage of 38 person-hours. CONCLUSIONS: Contact investigations are costly to the health care system. In a low-prevalence country, such as the United States, it is still important that health care providers are trained to think TB.

Vertebral size, bone density, and strength in men and women matched for age and areal spine BMD.

To explore the possible mechanisms underlying sex-specific differences in skeletal fragility that may be obscured by two-dimensional areal bone mineral density (aBMD) measures, we compared quantitative computed tomography (QCT)-based vertebral bone measures among pairs of men and women from the Framingham Heart Study Multidetector Computed Tomography Study who were matched for age and spine aBMD. Measurements included vertebral body cross-sectional area (CSA, cm(2) ), trabecular volumetric BMD (Tb.vBMD, g/cm(3) ), integral volumetric BMD (Int.vBMD, g/cm(3) ), estimated vertebral compressive loading and strength (Newtons) at L3 , the factor-of-risk (load-to-strength ratio), and vertebral fracture prevalence. We identified 981 male-female pairs (1:1 matching) matched on age (± 1 year) and QCT-derived aBMD of L3 (± 1%), with an average age of 51 years (range 34 to 81 years). Matched for aBMD and age, men had 20% larger vertebral CSA, lower Int.vBMD (-8%) and Tb.vBMD (-9%), 10% greater vertebral compressive strength, 24% greater vertebral compressive loading, and 12% greater factor-of-risk than women (p < 0.0001 for all), as well as higher prevalence of vertebral fracture. After adjusting for height and weight, the differences in CSA and volumetric bone mineral density (vBMD) between men and women were attenuated but remained significant, whereas compressive strength was no longer different. In conclusion, vertebral size, morphology, and density differ significantly between men and women matched for age and spine aBMD, suggesting that men and women attain the same aBMD by different mechanisms. These results provide novel information regarding sex-specific differences in mechanisms that underlie vertebral fragility.

Variations of CT-based trunk muscle attenuation by age, sex, and specific muscle.

BACKGROUND: Fat accumulation in muscle may contribute to age-related declines in muscle function and is indicated by reduced attenuation of x-rays by muscle tissue in computed tomography scans. Reduced trunk muscle attenuation is associated with poor physical function, low back pain, and increased hyperkyphosis in older adults. However, variations in trunk muscle attenuation with age, sex and between specific muscles have not been investigated. METHODS: A cross-sectional examination of trunk muscle attenuation in computed tomography scans was performed in 60 younger (35-50 years) and 60 older (75-87 years) adults randomly selected from participants in the Framingham Heart Study Offspring and Third Generation Multidetector Computed Tomography Study. Computed tomography attenuation of 11 trunk muscles was measured at vertebral levels T8 and L3, and the effects of age, sex, and specific muscle on computed tomography attenuation of trunk muscles were determined. RESULTS: Muscle attenuation varied by specific muscle (p < .001), was lower in older adults (p < .001), and was generally lower in women than in men (p < .001), although not in all muscles. Age-related differences in muscle attenuation varied with specific muscle (p < .001), with the largest age differences occurring in the paraspinal and abdominal muscles. CONCLUSIONS: Trunk muscle attenuation is lower in older adults than in younger adults in both women and men, but such age-related differences vary widely between muscle groups. The reasons that some muscles exhibit larger age-related differences in fat content than others should be further explored to better understand age-related changes in functional capacity and postural stability.

The effect of thoracic kyphosis and sagittal plane alignment on vertebral compressive loading.

To better understand the biomechanical mechanisms underlying the association between hyperkyphosis of the thoracic spine and risk of vertebral fracture and other degenerative spinal pathology, we used a previously validated musculoskeletal model of the spine to determine how thoracic kyphosis angle and spinal posture affect vertebral compressive loading. We simulated an age-related increase in thoracic kyphosis (T(1) -T(12) Cobb angle 50-75 degrees) during two different activities (relaxed standing and standing with 5-kg weights in the hands) and three different posture conditions: (1) an increase in thoracic kyphosis with no postural adjustment (uncompensated posture); (2) an increase in thoracic kyphosis with a concomitant increase in pelvic tilt that maintains a stable center of mass and horizontal eye gaze (compensated posture); and (3) an increase in thoracic kyphosis with a concomitant increase in lumbar lordosis that also maintains a stable center of mass and horizontal eye gaze (congruent posture). For all posture conditions, compressive loading increased with increasing thoracic kyphosis, with loading increasing more in the thoracolumbar and lumbar regions than in the mid-thoracic region. Loading increased the most for the uncompensated posture, followed by the compensated posture, with the congruent posture almost completely mitigating any increases in loading with increased thoracic kyphosis. These findings indicate that both thoracic kyphosis and spinal posture influence vertebral loading during daily activities, implying that thoracic kyphosis measurements alone are not sufficient to characterize the impact of spinal curvature on vertebral loading.

Regressions for estimating muscle parameters in the thoracic and lumbar trunk for use in musculoskeletal modeling.

Musculoskeletal modeling requires information on muscle parameters such as cross-sectional area (CSA) and moment arms. A variety of previous studies have reported muscle parameters in the trunk based on in vivo imaging, but there remain gaps in the available data as well as limitations in the generalizability of such data. Specifically, available trunk muscle CSA data is very limited for older adults, lacking entirely in the thoracic region. In addition, previous studies have made measurements in groups of healthy volunteers or hospital patients who may not be representative of the population in general. Finally, such studies have not reported data for the major muscles connecting the upper limb to the thoracic trunk. In this study, muscle morphology measurements were made for major muscles present in the trunk between vertebral levels T6 and L5 using quantitative computed tomography scans from a community-based sample of 100 men and women aged 36-87. We present regression equations to predict trunk muscle CSA and position relative to the vertebral body in the transverse plane from sex, age, height and weight at vertebral levels T6 to L5. Regressions were also developed for predicting anatomical CSA and muscle moment arms, which were estimated using literature data on muscle line of action. This work thus provides a resource for estimating muscle parameters in the general population for musculoskeletal modeling of the thoraco-lumbar trunk.

QCT measures of bone strength at the thoracic and lumbar spine: the Framingham Study.

We used volumetric quantitative computed tomography (QCT) scans to evaluate volumetric bone density (vBMD), geometry, and strength in the thoracic (T8 to T10) and lumbar (L3 to L5) spine and determined how these parameters varied with age, sex, and spinal region. Participants included 690 participants of the Framingham Study, 40 to 87 years old (mean, 61 years). In both women and men, trabecular vBMD declined with age similarly for lumbar and thoracic regions, whereas cortical vBMD and integral vBMD, vertebral strength, and compressive force declined more at the lumbar spine than thoracic spine (interaction, p < 0.01). Notably, in men, cortical vBMD increased (ß = 0.0004, p = 0.01), and vertebral strength did not change (ß = 1.9305, p = 0.66) at the thoracic spine with age. In both women and men, vertebral cross-sectional area increased less and the factor-of-risk increased more with age at the lumbar than at the thoracic region (interaction, p < 0.01). For example, in women, the factor-of-risk for forward flexion increased (worsened) with age 6.8-fold more in the lumbar spine (ß = 0.0157), compared with the thoracic spine (ß = 0.0023). vBMD and vertebral strength declined more and the factor-of-risk increased more with age in women than men (interaction, p < 0.01). For instance, integral vBMD for the lumbar spine declined 36% from 40 to 75 years of age in women compared with 18% in men. There was little or no age-related change in the forces applied to the thoracic vertebrae in either women or men. Age-related changes were greater in the lumbar spine than in the thoracic region and greater in women than men. Whereas women lost bone density and strength at both the thoracic and lumbar spine, in men, vertebral strength declined only at the lumbar spine. Our study confirms the importance of evaluating determinants of vertebral strength in both the thoracic and lumbar spine and in both women and men to understand mechanisms underlying the structural failure of vertebral bodies with aging.