27 research outputs found
Least squares optimization: From theory to practice
Nowadays, Nonlinear Least-Squares embodies the foundation of many Robotics and Computer Vision systems. The research community deeply investigated this topic in the last few years, and this resulted in the development of several open-source solvers to approach constantly increasing classes of problems. In this work, we propose a unified methodology to design and develop efficient Least-Squares Optimization algorithms, focusing on the structures and patterns of each specific domain. Furthermore, we present a novel open-source optimization system that addresses problems transparently with a different structure and designed to be easy to extend. The system is written in modern C++ and runs efficiently on embedded systemsWe validated our approach by conducting comparative experiments on several problems using standard datasets. The results show that our system achieves state-of-the-art performances in all tested scenarios
Behavioral and clinical characteristics of people receiving medical care for HIV infection in an outpatient facility in Sicily, Italy
Aim: The authors examined a cohort of HIV-positive outpatients at the AIDS Center of Palermo University in Italy in order to identify factors related to the frequency of their visits to the outpatient facility for health care services. Methods: Two hundred and twenty-four HIV-infected subjects were enrolled in the study. Demographic and HIV disease characteristics were recorded and assessed with the number of days accessed to our outpatients unit in univariate and multivariate analyses. The potential relationship with immunological status was also analyzed stratifying the patients into groups according to their CD4+ T-cell counts ( 65500 vs, \u2c2500/mm3, and 65200 vs < 200/mm3). Results: Both univariate and multivariate analyses showed that duration of antiretroviral therapy, \u2c25 years and hypertension were significantly associated with a CD4+ T-cell count of, \u2c2500/mm3, whereas geographic origin (Africa) was associated with a CD4+ T-cell count of, \u2c2200/mm3. Mean number of days the patients sought access to day-care services for laboratory tests was negatively associated with CD4+ T-cell count. Conclusion: Patients with low CD4+ T-cell counts showed higher use of health care services, demonstrating how early HIV diagnosis can help to reduce health care costs. The CD4+ T-cell cut-off of 200 cells emphasizes the importance of identifying and managing HIV infection among hard-to-reach groups like vulnerable migrants. In our sle, the illegal status of immigrants does not influence the management of their HIV/AIDS condition, but the lack of European health card that documents the current antiretroviral status, could interfere with the efforts to eradicate AIDS. A better understanding of the major determinants of HIV treatment costs has led to appropriate large-scale actions, which in turn has increased resources and expanded intervention programs. Further guidance should be offered to hard-to-reach groups in order to improve early AIDS diagnosis, and procedures for identifying and managing these vulnerable subjects should be made available to care commissioners and service providers
VDBFusion: Flexible and Efficient TSDF Integration of Range Sensor Data
Mapping is a crucial task in robotics and a fundamental building block of most mobile systems deployed in the real world. Robots use different environment representations depending on their task and sensor setup. This paper showcases a practical approach to volumetric surface reconstruction based on truncated signed distance functions, also called TSDFs. We revisit the basics of this mapping technique and offer an approach for building effective and efficient real-world mapping systems. In contrast to most state-of-the-art SLAM and mapping approaches, we are making no assumptions on the size of the environment nor the employed range sensor. Unlike most other approaches, we introduce an effective system that works in multiple domains using different sensors. To achieve this, we build upon the Academy-Award-winning OpenVDB library used in filmmaking to realize an effective 3D map representation. Based on this, our proposed system is flexible and highly effective and, in the end, capable of integrating point clouds from a 64-beam LiDAR sensor at 20 frames per second using a single-core CPU. Along with this publication comes an easy-to-use C++ and Python library to quickly and efficiently solve volumetric mapping problems with TSDFs
DCPCR: Deep Compressed Point Cloud Registration in Large-Scale Outdoor Environments
Reliable and accurate registration of point clouds is a challenging problem in robotics as well as in the domain of autonomous driving. In this article, we address the task of aligning point clouds with low overlap, containing moving objects, and without prior information about the initial guess. We enhance classical ICP-based registration with neural feature-based matching to reliably find point correspondences. Our novel 3D convolutional and attention-based network is trained in an end-to-end fashion to learn features, which are well suited for matching and for rating the quality of the point correspondences. By utilizing a compression encoder, we can directly operate on a compressed map representation, making our approach well suited for operation under memory constraints. We evaluate our approach on point clouds obtained at completely different points in time, showing that our approach is able to register point clouds even under those challenging conditions reliably
miR-204 overexpression exerts a protective role in inherited retinal diseases
Purpose : Inherited retinal diseases (IRDs) are progressive neurodegenerative conditions of the retina that represent a main cause of genetic blindness in the Western world. Their high genetic heterogeneity hinders the development of effective gene-based therapies. We have recently demonstrated that the microRNA miR-204 is essential for retinal function and plays a pathogenic role in IRD in humans. Therefore, we aimed at assessing the potential therapeutic action of this microRNA in IRDs.
Methods : We delivered by subretinal injection an adeno-associated viral vector carrying the miR-204 precursor to the Aipl1knockout and the P347S-RHOtransgenic mouse lines, models of autosomal recessive and dominant forms of IRDs, respectively. The impact on retinal function and degeneration was assessed by electroretinographic and immunohistological analyses.
Results : We detected a notable improvement of the ERG response in the miR-204-injected eyes of P347S-RHOmice. This effect persisted for two months post-injection and was prevalent in conditions reflecting mixed cone-rod responses. We also observed a preservation of cone photoreceptors and a significant decrease in apoptotic photoreceptor cells. Photoreceptors were better preserved also in miR204-injected eyes of Aipl1 knockoutmice. Transcriptome analysis suggested that dampening of microglia activation represents one of the main mechanisms underlying the neuroprotective effect of miR-204.
Conclusions : Our findings indicate that the subretinal delivery of miR-204 attenuates retinal degeneration in IRD mouse models and preserves retinal function, supporting the gene-independent therapeutic potential of this microRNA
AAV-miR-204 Protects from Retinal Degeneration by Attenuation of Microglia Activation and Photoreceptor Cell Death
Inherited retinal diseases (IRDs) represent a frequent cause of genetic blindness. Their high genetic heterogeneity hinders the application of gene-specific therapies to the vast majority of patients. We recently demonstrated that the microRNA miR-204 is essential for retinal function, although the underlying molecular mechanisms remain poorly understood. Here, we investigated the therapeutic potential of miR-204 in IRDs. We subretinally delivered an adeno-associated viral (AAV) vector carrying the miR-204 precursor to two genetically different IRD mouse models. The administration of AAV-miR-204 preserved retinal function in a mouse model for a dominant form of retinitis pigmentosa (RHO-P347S). This was associated with a reduction of apoptotic photoreceptor cells and with a better preservation of photoreceptor marker expression. Transcriptome analysis showed that miR-204 shifts expression profiles of transgenic retinas toward those of healthy retinas by the downregulation of microglia activation and photoreceptor cell death. Delivery of miR-204 exerted neuroprotective effects also in a mouse model of Leber congenital amaurosis, due to mutations of the Aipl1 gene. Our study highlights the mutation-independent therapeutic potential of AAV-miR204 in slowing down retinal degeneration in IRDs and unveils the previously unreported role of this miRNA in attenuating microglia activation and photoreceptor cell death
Behavioral and clinical characteristics of people receiving medical care for HIV infection in an outpatient facility in Sicily, Italy
Paola Di Carlo,1 Giuliana Guadagnino,1 Palmira Immordino,1 Giovanni Mazzola,2 Pietro Colletti,2 Ilenia Alongi,1 Lucia Adamoli,1 Francesco Vitale,1 Alessandra Casuccio1 1Department of Sciences for Health Promotion and Mother-Child Care “G D’Alessandro”, University of Palermo, 2Department of Medicinal Clinics and Emerging Diseases, “Paolo Giaccone” Polyclinic University Hospital, Palermo, Italy Aim: The authors examined a cohort of HIV-positive outpatients at the AIDS Center of Palermo University in Italy in order to identify factors related to the frequency of their visits to the outpatient facility for health care services.Methods: Two hundred and twenty-four HIV-infected subjects were enrolled in the study. Demographic and HIV disease characteristics were recorded and assessed with the number of days accessed to our outpatients unit in univariate and multivariate analyses. The potential relationship with immunological status was also analyzed stratifying the patients into groups according to their CD4+ T-cell counts (≥500 vs <500/mm3, and ≥200 vs <200/mm3).Results: Both univariate and multivariate analyses showed that duration of antiretroviral therapy <5 years and hypertension were significantly associated with a CD4+ T-cell count of <500/mm3, whereas geographic origin (Africa) was associated with a CD4+ T-cell count of <200/mm3. Mean number of days the patients sought access to day-care services for laboratory tests was negatively associated with CD4+ T-cell count.Conclusion: Patients with low CD4+ T-cell counts showed higher use of health care services, demonstrating how early HIV diagnosis can help to reduce health care costs. The CD4+ T-cell cut-off of 200 cells emphasizes the importance of identifying and managing HIV infection among hard-to-reach groups like vulnerable migrants. In our sample, the illegal status of immigrants does not influence the management of their HIV/AIDS condition, but the lack of European health card that documents the current antiretroviral status, could interfere with the efforts to eradicate AIDS. A better understanding of the major determinants of HIV treatment costs has led to appropriate large-scale actions, which in turn has increased resources and expanded intervention programs. Further guidance should be offered to hard-to-reach groups in order to improve early AIDS diagnosis, and procedures for identifying and managing these vulnerable subjects should be made available to care commissioners and service providers. Keywords: HIV infection, CD4+ T-cell count, access to care, HIV outpatient service, hard-to-reach groups, resource us
Current practice of hepatitis C treatment in Southern Italy.
BACKGROUND: Only a small proportion of subjects referring to hospitals for hepatitis C virus (HCV) positivity receives antiviral therapy.
AIM: To evaluate the rate of antiviral treatment and the causes for no treatment in HCV-RNA positive subjects seen in hospital settings.
PATIENTS AND METHODS: A prospective study enrolling over a 6-month period (February-July 2009) all consecutive anti-HCV positive subjects initially referred (naïve patients) to 12 liver units in Southern Italy for HCV treatment.
RESULTS: Out of 608 subjects evaluated, 74 (12.2%) had no detectable HCV-RNA in the serum and thus were excluded. Of the remaining 534 HCV-RNA positive subjects, 357 (66.9%) were not treated for the following reasons: 49.9% were older than 65 years of age (75% of them >70 years), 14.3% had normal liver enzymes, 13.2% had compensated/decompensated cirrhosis, 10.4% refused treatment, 9.8% had ongoing substance or alcohol abuse. Multivariate analysis showed that females (O.R. 2.27; C.I. 95% 1.05-4.90) and subjects with low educational level (O.R. 4.38; C.I. 95% 1.27-15.11) were more likely to decline therapy.
CONCLUSIONS: The majority of patients with HCV infection does not receive antiviral treatment. The effectiveness of the current standard therapy for HCV infection is low despite its good efficacy
Comparison between heroin and heroin-cocaine polyabusers: a psychopathological study
The concomitant use of cocaine by heroin-dependent subjects,
or by patients on methadone maintenance treatment, is a relevant
phenomenon that determines the negative consequences on health, social
adjustment, and outcome of opioid addiction treatment. Little is known
about the patterns of co-use of these two substances and the pathophysiological
alterations following this condition. Only a few studies have
evaluated the neurochemical effects in subjects carrying this specific
pattern of abuse. Similarly, the impact of cocaine abuse on psychiatric
and social function in subjects already affected by opioid addiction is
still poorly understood and further studies are necessary to investigate
this specific area that could profoundly affect methadone maintenance
treatment. The aim of this article is to investigate the psychopathological
symptoms of heroin–cocaine abuse in a group of heroin addicts applying
for treatment. Results show a direct relationship between cocaine abuse
and a higher rate of psychiatric disorders, but a negative correlation with
the severity of self-rated psychopathology