Deep Projective 3D Semantic Segmentation

Semantic segmentation of 3D point clouds is a challenging problem with numerous real-world applications. While deep learning has revolutionized the field of image semantic segmentation, its impact on point cloud data has been limited so far. Recent attempts, based on 3D deep learning approaches (3D-CNNs), have achieved below-expected results. Such methods require voxelizations of the underlying point cloud data, leading to decreased spatial resolution and increased memory consumption. Additionally, 3D-CNNs greatly suffer from the limited availability of annotated datasets. In this paper, we propose an alternative framework that avoids the limitations of 3D-CNNs. Instead of directly solving the problem in 3D, we first project the point cloud onto a set of synthetic 2D-images. These images are then used as input to a 2D-CNN, designed for semantic segmentation. Finally, the obtained prediction scores are re-projected to the point cloud to obtain the segmentation results. We further investigate the impact of multiple modalities, such as color, depth and surface normals, in a multi-stream network architecture. Experiments are performed on the recent Semantic3D dataset. Our approach sets a new state-of-the-art by achieving a relative gain of 7.9 %, compared to the previous best approach.Comment: Submitted to CAIP 201

Socioeconomic and behavioral factors associated with tuberculosis diagnostic delay in Lima, Peru

Early detection and diagnosis of tuberculosis (TB) is a global priority. Prolonged symptom duration prior to TB diagnosis is associated with increased morbidity, mortality and risk of transmission. We aimed to determine socioeconomic and behavioral factors associated with diagnostic delays among patients with TB. Data were collected from 105 patients with TB using a semi-structured interview guide in Lima, Peru. Factors associated with diagnostic delay were analyzed using negative binomial regression. The median delay from when symptoms commenced and the first positive diagnostic sample in public health facilities was 57 days (interquartile range (IQR): 28-126). In multivariable analysis, greater diagnostic delay was independently associated with patient older age; female sex; lower personal income prior to diagnosis; living with fewer people; and having more visits to professional health facilities prior to diagnosis (all p<0.05). Patients who first sought care at a private health facility had more visits overall to professional health facilities prior to diagnosis than those who first sought care from public or insured employee health facilities and had longer diagnostic delay in analysis adjusted for age and sex. Patients with TB were significantly more likely to first self-medicate than to visit professional health facilities prior to diagnosis (p=0.003). Thus, diagnostic delay was prolonged, greatest among older, low-income women and varied according to the type of care sought by individuals when their symptoms commenced. These findings suggest that TB case finding initiatives should target vulnerable groups in informal and private health facilities, where many patients with TB first seek healthcare

Why wait? The social determinants underlying tuberculosis diagnostic delay.

BACKGROUND: Early detection and diagnosis of tuberculosis remain major global priorities for tuberculosis control. Few studies have used a qualitative approach to investigate the social determinants contributing to diagnostic delay and none have compared data collected from individual, community, and health-system levels. We aimed to characterize the social determinants that contribute to diagnostic delay among persons diagnosed with tuberculosis living in resource-constrained settings. METHODS/PRINCIPLE FINDINGS: Data were collected in public health facilities with high tuberculosis incidence in 19 districts of Lima, Peru. Semi-structured interviews with persons diagnosed with tuberculosis (n = 105) and their family members (n = 63) explored health-seeking behaviours, community perceptions of tuberculosis and socio-demographic circumstances. Focus groups (n = 6) were conducted with health personnel (n = 35) working in the National Tuberculosis Program. All interview data were transcribed and analysed using a grounded theory approach. The median delay between symptom onset and the public health facility visit that led to the first positive diagnostic sample was 57 days (interquartile range 28-126). The great majority of persons diagnosed with tuberculosis distrusted the public health system and sought care at public health facilities only after exhausting other options. It was universally agreed that persons diagnosed with tuberculosis faced discrimination by public and health personnel. Self-medication with medicines bought at local pharmacies was reported as the most common initial health-seeking behaviour due to the speed and low-cost of treatment in pharmacies. Most persons diagnosed with tuberculosis initially perceived their illness as a simple virus. CONCLUSIONS: Diagnostic delay was common and prolonged. When individuals reached a threshold of symptom severity, they addressed their health with the least time-consuming, most economically feasible, and well-known healthcare option available to them. In high-burden settings, more human and material resources are required to promote tuberculosis case-finding initiatives, reduce tuberculosis associated stigma and address the social determinants underlying diagnostic delay

Floor feeding sows their daily allocation over multiple drops per day does not result in more equitable feeding opportunities in later drops

This research studied whether floor feeding group-housed sows their daily allocation overmultiple feed drops per day provides more equitable feeding opportunities in later drops. Over four time replicates, 275 sows were mixed into groups of 10 for both their first and second gestations (200 sows/gestation, 126 sows observed in both gestations). The feeding behavior of individual sows was recorded for 10 min following each of four feed drops per day (0730, 0900, 1100, 1500 h) on days 2, 9 and 51 post-mixing. The location of feeding sows (i.e., feeding in areas associated with high, reduced or little/no food availability) was also recorded. Sow aggressive behavior on day 2 was used to classify sows as dominant (D), subdominant (SD), or submissive (SM). Dominant sows spent the most time feeding in areas of high-food availability (gestation 1, p p = 0.023); SD sows fed more frequently than D sows from areas of reduced food availability (gestation 1, p = 0.001; gestation 2, p = 0.025); and SM sows performed more feeding behavior in areas of little/no food availability (gestation 1, p p p > 0.05). Further research on the management and design of floor feeding systems is required, with a particular emphasis on increasing accessibility to sows that avoid the feeding area

Type 2 diabetes mellitus and antibiotic-resistant infections: A Systematic Review and meta-analysis

Background: Type 2 diabetes mellitus (T2DM) has been associated with infectious diseases; however, whether T2DM is associated with bacterial-resistant infections has not been thoroughly studied. We ascertained whether people with T2DM were more likely to experience resistant infections in comparison to T2DM-free individuals. Methods: Systematic review and random-effects meta-analysis. The search was conducted in Medline, Embase, and Global Health. We selected observational studies in which the outcome was resistant infections (any site), and the exposure was T2DM. We studied adult subjects who could have been selected from population-or hospital-based studies. I-squared was the metric of heterogeneity. We used the Newcastle-Ottawa risk of bias scale. Results: The search retrieved 3,370 reports, 97 were studied in detail and 61 (449,247 subjects) were selected. Studies were mostly cross-sectional or case-control; several infection sites were studied, but mostly urinary tract and respiratory infections. The random-effects meta-analysis revealed that people with T2DM were two-fold more likely to have urinary tract (OR= 2.42; 95% CI: 1.83-3.20; I-squared 19.1%) or respiratory (OR= 2.35; 95% CI: 1.49-3.69; I-squared 58.1%) resistant infections. Although evidence for other infection sites was heterogeneous, they consistently suggested that T2DM was 66associated with resistant infections. Conclusions: Compelling evidence suggests that people with T2DM are more likely to experience antibiotic-resistant urinary tract and respiratory infections. The evidence for other infection sites was less conclusive but pointed to the same overall conclusion. These results could guide empirical treatment for patients with T2DM and infections

Usefulness of an Intrapartum Ultrasound Simulator (IUSim™) for Midwife Training: Results from an RCT

Introduction: We conducted a randomized study to determine whether a training session on a dedicated simulator (IUSim™) would facilitate the midwives in learning the technique of transperineal intrapartum ultrasound. Methods: Following a 30-min multimedia presentation including images and videos on how to obtain and measure the angle of progression (AoP) and the head-perineum distance (HPD), 6 midwives with no prior experience in intrapartum ultrasound were randomly split into 2 groups: 3 of them were assigned to the "training group"and 3 to the "control group."The midwives belonging to the former group were taught to measure the 2 sonographic parameters during a 3-h practical session conducted on IUSim™ under the supervision of an expert obstetrician. In the following 3 months, all the 6 midwives were asked to independently perform transperineal ultrasound during their clinical practice and to measure on the acquired images either the AoP or the HPD. The sonographic images were examined in blind by the teaching obstetrician who assigned a 0-3 score to the image quality (IQS) and to the measurement quality (MQS). Results: A total of 48 ultrasound images (24 patients) from 5 midwives were acquired and included in the study analysis. A midwife of the "training group"declined participation after the practical session. Independently from the randomization group, the image quality score (IQS + MQS) was significantly higher for the HPD compared with the AoP (2.5 ± 0.66 vs. 1.79 ± 1.14; p = 0.01). In the training group, the MQS of either AoP (2.66 ± 0.5 vs.1.46 ± 1.45. p = 0.038) and the HPD (2.9 ± 0.33 vs. 1.87 ± 0.83 p = 0.002) was significantly higher in comparison with the control group, while the IQS of both measurements was comparable between the 2 groups (1.91 ± 1.24 vs. 2.25 ± 0.865; p = 0.28). Conclusion: The use of a dedicated simulator may facilitate the midwives in learning how to measure the AoP and the HPD on transperineal ultrasound images

Evaluación del balance de masa de un Glaciar Antártico: Glaciar Znosko, estudio final

El glaciar Znosko se encuentra ubicado en la isla Rey Jorge, que forma parte de las islas Shetland del Sur. El área total del glaciar para el año 2020 fue de 1.72 km2, de los cuales 1.6 km2 se encontraban expuestos. El glaciar se ubica a menos de 600 metros de distancia de la Estación Científica Antártica Macchu Picchu (ECAMP), la cual opera desde el año 1989. En diferentes expediciones científicas (ANTAR) se observó de forma visual su pérdida de masa glaciar, razón por la que en el año 2018 se inició el monitoreo de este glaciar mediante la instalación de 19 estacas en la zona de ablación y la toma de testigos de hielo en la zona de acumulación, actividades que se mantuvieron durante los veranos australes de los años 2019 y 2020, estando la recuperación de información sobre el glaciar supeditada a las condiciones meteorológicas. El balance de masa del glaciar Znosko obtenido para los años 2018-19 y 2019-20 ascendió a – 590.7 mm.w.e. y -686.7 mm.w.e. (milímetros equivalentes en agua por sus siglas inglés), respectivamente. Considerando que el monitoreo de este glaciar será una actividad científica permanente, en este artículo se describe la metodología que condujo a la obtención de esta información a ser implementada en un procedimiento futuro