Improving LiDAR 3D Object Detection via Range-based Point Cloud Density Optimization

In recent years, much progress has been made in LiDAR-based 3D object detection mainly due to advances in detector architecture designs and availability of large-scale LiDAR datasets. Existing 3D object detectors tend to perform well on the point cloud regions closer to the LiDAR sensor as opposed to on regions that are farther away. In this paper, we investigate this problem from the data perspective instead of detector architecture design. We observe that there is a learning bias in detection models towards the dense objects near the sensor and show that the detection performance can be improved by simply manipulating the input point cloud density at different distance ranges without modifying the detector architecture and without data augmentation. We propose a model-free point cloud density adjustment pre-processing mechanism that uses iterative MCMC optimization to estimate optimal parameters for altering the point density at different distance ranges. We conduct experiments using four state-of-the-art LiDAR 3D object detectors on two public LiDAR datasets, namely Waymo and ONCE. Our results demonstrate that our range-based point cloud density manipulation technique can improve the performance of the existing detectors, which in turn could potentially inspire future detector designs

Adoption of social media marketing for sustainable business growth of SMEs in emerging economies: The moderating role of leadership support

Social media marketing (SMM) plays an important role in business communication, mar-keting, operations, and other activities. There is a growing interest among researchers, academicians, and practitioners to understand the role of SMM in business sustainability in small and medium enterprises (SMEs) in an emerging economy, like India. Few studies have attempted to understand this role. Thus, the aim of this study is to examine the impact of adopting social media marketing for sustainable business growth of SMEs in an emerging economy. The study also investigates the moderating role of SME leadership support on the relationship between SMM usage and sustainable business growth of SMEs. After reviewing the existing literature and technology adoption model, a theoretical model is developed, which is then validated using a structural equation modeling tech-nique to analyze 304 samples of Indian SMEs that use different social media marketing applications in their enterprises. This study confirmed that SMM tools significantly and positively improve the sustainable growth of SMEs in an emerging economy. Additionally, the study also found that SME leadership team plays a vital role in supporting actual usage of SMM tools that accelerate sustainable business growth of SMEs

Spontaneous ventral urethral fistula in a young diabetic man: a case report

We present the first case reported in the medical literature of a patient with a spontaneous ventral urethral fistula accompanied by severe infection due to diabetes mellitus. A 34-year-old man with poor controlled adult-onset diabetes mellitus was admitted to our hospital with a large subcutaneous abscess involving the complete penis, scrotum and perineum. The patient did not report any history of any penile trauma or local infection but has experienced transient swelling of the perineal region following urination. Initial surgical treatment consisted of surgical debridement of necrotic tissue. At this time reconstructive surgery was impossible and a suprapubic cystostomy was performed. After 4 months of suprapubic urinary diversion the urethral fistula resolved and function of external genitalia was reestablished. In a follow-up period of 40 months no recurrence occurred. Spontaneous diabetes-associated ventral urethral fistulas are extremely rare and we are not aware of any other published case report

Generating Optimal Topologies in Structural Design Using a Homogenization Method,"

This paper proposes a basic method for designing light and rigid structures that have a maximum natural frequency for a designated mode. A design variable "density," related to the material properties of a three-dimensional solid element, is introduced into the finite element method ( FEM ). Thus, a structure is expressed as a density distribution inside its design domain, and the optimal structure is obtained by searching for the most suitable such distribution

Age- and sex-based heterogeneity in coronary artery plaque presence and burden in familial hypercholesterolemia:A multi-national study

Objectives: Individuals with familial hypercholesterolemia (FH) are at an increased risk for coronary artery disease (CAD). While prior research has shown variability in coronary artery calcification (CAC) among those with FH, studies with small sample sizes and single-center recruitment have been limited in their ability to characterize CAC and plaque burden in subgroups based on age and sex. Understanding the spectrum of atherosclerosis may result in personalized risk assessment and tailored allocation of costly add-on, non-statin lipid-lowering therapies. We aimed to characterize the presence and burden of CAC and coronary plaque on computed tomography angiography (CTA) across age- and sex-stratified subgroups of individuals with FH who were without CAD at baseline. Methods: We pooled 1,011 patients from six cohorts across Brazil, France, the Netherlands, Spain, and Australia. Our main measures of subclinical atherosclerosis included CAC ranges (i.e., 0, 1–100, 101–400, &gt;400) and CTA-derived plaque burden (i.e., no plaque, non-obstructive CAD, obstructive CAD). Results: Ninety-five percent of individuals with FH (mean age: 48 years; 54% female; treated LDL-C: 154 mg/dL) had a molecular diagnosis and 899 (89%) were on statin therapy. Overall, 423 (42%) had CAC=0, 329 (33%) had CAC 1–100, 160 (16%) had CAC 101–400, and 99 (10%) had CAC &gt;400. Compared to males, female patients were more likely to have CAC=0 (48% [n = 262] vs 35% [n = 161]) and no plaque on CTA (39% [n = 215] vs 26% [n = 120]). Among patients with CAC=0, 85 (20%) had non-obstructive CAD. Females also had a lower prevalence of obstructive CAD in CAC 1–100 (8% [n = 15] vs 18% [n = 26]), CAC 101–400 (32% [n = 22] vs 40% [n = 36]), and CAC &gt;400 (52% [n = 16] vs 65% [n = 44]). Female patients aged 50–59 years were less likely to have obstructive CAD in CAC &gt;400 (55% [n = 6] vs 70% [n = 19]). Conclusion: In this large, multi-national study, we found substantial age- and sex-based heterogeneity in CAC and plaque burden in a cohort of predominantly statin-treated individuals with FH, with evidence for a less pronounced increase in atherosclerosis among female patients. Future studies should examine the predictors of resilience to and long-term implications of the differential burden of subclinical coronary atherosclerosis in this higher risk population.</p

Association of Noncontrast Computed Tomography and Perfusion Modalities With Outcomes in Patients Undergoing Late-Window Stroke Thrombectomy

Importance: There is substantial controversy with regards to the adequacy and use of noncontrast head computed tomography (NCCT) for late-window acute ischemic stroke in selecting candidates for mechanical thrombectomy. Objective: To assess clinical outcomes of patients with acute ischemic stroke presenting in the late window who underwent mechanical thrombectomy stratified by NCCT admission in comparison with selection by CT perfusion (CTP) and diffusion-weighted imaging (DWI). Design, setting, and participants: In this multicenter retrospective cohort study, prospectively maintained Stroke Thrombectomy and Aneurysm (STAR) database was used by selecting patients within the late window of acute ischemic stroke and emergent large vessel occlusion from 2013 to 2021. Patients were selected by NCCT, CTP, and DWI. Admission Alberta Stroke Program Early CT Score (ASPECTS) as well as confounding variables were adjusted. Follow-up duration was 90 days. Data were analyzed from November 2021 to March 2022. Exposures: Selection by NCCT, CTP, or DWI. Main outcomes and measures: Primary outcome was functional independence (modified Rankin scale 0-2) at 90 days. Results: Among 3356 patients, 733 underwent late-window mechanical thrombectomy. The median (IQR) age was 69 (58-80) years, 392 (53.5%) were female, and 449 (65.1%) were White. A total of 419 were selected with NCCT, 280 with CTP, and 34 with DWI. Mean (IQR) admission ASPECTS were comparable among groups (NCCT, 8 [7-9]; CTP, 8 [7-9]; DWI 8, [7-9]; P = .37). There was no difference in the 90-day rate of functional independence (aOR, 1.00; 95% CI, 0.59-1.71; P = .99) after adjusting for confounders. Symptomatic intracerebral hemorrhage (NCCT, 34 [8.6%]; CTP, 37 [13.5%]; DWI, 3 [9.1%]; P = .12) and mortality (NCCT, 78 [27.4%]; CTP, 38 [21.1%]; DWI, 7 [29.2%]; P = .29) were similar among groups. Conclusions and relevance: In this cohort study, comparable outcomes were observed in patients in the late window irrespective of neuroimaging selection criteria. Admission NCCT scan may triage emergent large vessel occlusion in the late window