Bayesian Population Size Estimation With a Single Sample

La stima della numerosit`a di una popolazione `e un problema comune a vari ambiti di applicazione. Le procedure di stima sono solitamente basate sul noto metodo cattura-ricattura, il quale comporta elevati costi e disturbo della popolazione. Tali considerazioni hanno stimolato la ricerca di tecniche che permettano di ottenere un stima utilizzando un unico campione. Hettiarachchige (Hettiarachchige, C.K.H.: Inference from single occasion capture experiments using genetic markers. PhD Thesis (2016)) propone un metodo applicabile nel caso in cui la popolazione sia composta di due sole generazioni: un gruppo di unit`a generatrici ed uno di unit`a generate. L’obiettivo del nostro lavoro `e quello di ottenere un’estensione Bayesiana dell’originale modello frequentista. Risultati preliminari evidenziano accuratezza degli stimatori Bayesiani sensibilmente migliore rispetto alle alternative frequentiste.The estimation of the size of a finite population is a problem encountered in a variety of applications. One standard statistical approach relies on markrecapture sampling, which may require high costs and annoyance to the population of interest. These considerations have motivated the search for alternative sampling strategies that allow to estimate the size of a population from a single capture. Hettiarachchige (Hettiarachchige, C.K.H.: Inference from single occasion capture experiments using genetic markers. PhD Thesis (2016)) proposes a method that is viable when the population is made of only two generations: a group of generators and one of generated units. We investigate Bayesian methods alternative to the frequentist estimators used by the original author. Preliminary results give evidence of competing performance of the Bayesian approach, which in some cases sensibly outperforms the frequentist alternatives

Emotional Awareness During Bug Fixes – A Pilot Study

This study examines the effects of a programmer\u27s emotional awareness on progress while fixing bugs. The goal of the study is to capitalize on emotional awareness to ultimately increase progress made during software development. This process could result in improved software maintenance

LiDARs detected signal and Target distance estimation: measurement errors from Target reflectance and multiple echos

The use of LiDARs in automotive is increasingly widespread. In order to operate in a critical environment such as that of mobility, these systems must offer increasingly high performance. In particular, the ability to estimate the position of objects regardless of their reflectance and presence of diffusing backgrounds is a very sought-after feature by manufacturers. In commercial systems various strategies are used to make the measurement as insensitive as possible to these effects, however, it is not possible to fully compensate for the measurement errors caused by them. In this paper, we propose two simple experimental setups to verify the presence of these measurement errors in two scenarios. Moreover, we report the performance of a commercial LiDAR (MRS 6000 by Sick) using certified reflectance standards (Spectralon (R) Diffuse Reflectance Standards, by Labsphere). For this LiDAR, the results obtained show that a logarithmic variation of the reflectance of the target of 1.26-log at a target distance 2.4 m provides incompatible measurements. Furthermore, the presence of a background at a distance shorter than 11 cm, 12 cm and 13 cm respectively with 50 %, 75 % and 99 % reflectance also provides incompatible measurements for a target distance of 1.3 m from the LiDAR

Comparison of VLP-16 and MRS-1000 LiDAR systems with absolute interferometer

Nowadays, LiDARs hold a relevant place in providing the environmental sensing required by most ADAS. Promoted by such increasing demand, many new manufacturers are emerging and, new LiDARs are continuously made available on the market. If, on the one hand, the availability of LiDARs with increasing performance and reducing cost has brought significant benefits also promoting the spread of such measuring systems in other areas such as industrial controls and agriculture, on the other, it has made it more difficult to extricate in the immense set of LiDARs present on the market today. In response to this growing need for standards and methods capable of comparing the various LiDARs, many international standards and scientific publications are being produced on the subject. In this paper, we continue our work on LiDARs characterization, focusing our attention on comparing the performances of two of the must popular systems - namely, the MRS 1000 by Sick and the VLP 16 by Velodyne. Starting from the analysis of the warm-up time and stability, such a comparison focused on analyzing the axial error of both systems. Such errors have been estimated by exploiting a custom rail system and an absolute interferometer. The obtained results revealed warm-up times of a few tens of minutes and maximum absolute axial errors of a few centimeters in the range [1.5,21] m

Analysis, Quantification, and Discussion of the Approximations Introduced by Pulsed 3-D LiDARs

Light detection and rangings (LiDARs) are considered essential for the environmental sensing required by most advanced driver assistance system (ADAS), including autonomous driving. This has led to significant investments resulted in the availability of countless measuring systems that are increasingly performing and less expensive. Nevertheless, the extremely high speed of light still leads to a nonnegligible quantization error in the direct time-of-flight (ToF) measure at the base of pulsed LiDARs-the leading technology for automotive applications. Hence, pulsed 3-D LiDARs analyze the surrounding by approximating and deforming it on concentric spheres whose radii are quantized with a quantization step that, for most commercial systems, is on the order of some centimeters. The deformation and error introduced by such quantization can thus he significant. In this study, we point out the approximations and assumptions intrinsic to 3-D LiDARs and propose a measurement procedure that, through the analysis of the fine variations of the target position, allows an accurate investigation of the axial resolution and error-probably among the few limitations still affecting this technology. To the best of our knowledge, this is the first study focused on the detailed analysis of the quantization error in 3-D LiDARs. The proposed method has been tested on one of the most popular 3-D LiDARs, namely the MRS 6000 by Sick. The obtained results revealed for the MRS 6000 a quantization step of about 6 cm (ToF quantization of about 0.4 ns) and an axial error normally distributed with experimental standard deviation of about 30 mm

A simple method for the preliminary analysis and benchmarking of automotive LiDARs in fog

The vast multitude of LiDAR systems currently available on the market makes the need for methods to compare their performances increasingly high. In this study, we focus our attention on the development of a method for the analysis of the effects induced by the fog, one of the main challenges for Advanced Driver Assist Systems (ADASs) and autonomous driving. Large experimental setups capable of reconstructing adverse weather conditions on a large scale in a controlled and repeatable way are certainly the best test conditions to analyze and compare LiDARs performances in the fog. Nonetheless, such large plants are extremely expensive and complex, therefore only available in a few sites in the world. In this study, we thus propose a measurement method, a data analysis procedure and, an experimental setup that are extremely simple and inexpensive to implement. The achievable results are reasonably less accurate than those obtainable with large plants. Nevertheless, the proposed method can allow to easily and quickly obtain a preliminary estimate of the performance in the presence of fog and a rapid benchmarking of different LiDAR systems

Emotional Awareness During Bug Fixes – A Pilot Study

This study examines the effects of a programmer\u27s emotional awareness on progress while fixing bugs. The goal of the study is to capitalize on emotional awareness to ultimately increase progress made during software development. This process could result in improved software maintenance

Ruthenium-Catalyzed Decarboxylative Rearrangement of 4-Alkenyl-isoxazol-5-ones to Pyrrole Derivatives

Easily accessible isoxazol-5(4H)-ones are useful precursors of heterocycles. In this context, we report the ruthenium-catalyzed transformation of 4-alkenyl-substituted isoxazol-5-ones to afford 1H-pyrrole derivatives. The operative conditions were proven to be effective also on cyclohexane-fused isoxazolones giving 4,5,6,7-tetrahydroindoles. The reactions, which allow for access to tri-and tetra-substituted pyrroles in moderate to high yields, occur through decarboxylative ring-opening/ring-closure involving C-H functionalization of the alkenyl moiety

Aberrant splicing and expression of the non muscle myosin heavy-chain gene MYH14 in DM1 muscle tissues

Myotonic dystrophy type 1 (DM1) is a complex multisystemic disorder caused by an expansion of a CTG repeat located at the 3' untranslated region (UTR) of DMPK on chromosome 19q13.3. Aberrant messenger RNA (mRNA) splicing of several genes has been reported to explain some of the symptoms of DM1 including insulin resistance, muscle wasting and myotonia. In this paper we analyzed the expression of the MYH14 mRNA and protein in the muscle of DM1 patients (n=12) with different expansion lengths and normal subjects (n=7). The MYH14 gene is located on chromosome 19q13.3 and encodes for one of the heavy chains of the so called class II "nonmuscle" myosins (NMHCII). MYH14 has two alternative spliced isoforms: the inserted isoform (NMHCII-C1) which includes 8 amino acids located in the globular head of the protein, not encoded by the non inserted isoform (NMHCII-C0). Results showed a splicing unbalance of the MYH14 gene in DM1 muscle, with a prevalent expression of the NMHCII-C0 isoform more marked in DM1 patients harboring large CTG expansions. Minigene assay indicated that levels of the MBNL1 protein positively regulates the inclusion of the MYH14 exon 6. Quantitative analysis of the MYH14 expression revealed a significant reduction in the DM1 muscle samples, both at mRNA and protein level. No differences were found between DM1 and controls in the skeletal muscle localization of MYH14, obtained through immunofluorescence analysis. In line with the thesis of an "RNA gain of function" hypothesis described for the CTG mutation, we conclude that the alterations of the MYH14 gene may contribute to the DM1 molecular pathogenesis

Cyclin D1 Restrains Oncogene-Induced Autophagy by Regulating the AMPK-LKB1 Signaling Axis.

Autophagy activated after DNA damage or other stresses mitigates cellular damage by removing damaged proteins, lipids, and organelles. Activation of the master metabolic kinase AMPK enhances autophagy. Here we report that cyclin D1 restrains autophagy by modulating the activation of AMPK. In cell models of human breast cancer or in a cyclin D1-deficient model, we observed a cyclin D1-mediated reduction in AMPK activation. Mechanistic investigations showed that cyclin D1 inhibited mitochondrial function, promoted glycolysis, and reduced activation of AMPK (pT172), possibly through a mechanism that involves cyclin D1-Cdk4/Cdk6 phosphorylation of LKB1. Our findings suggest how AMPK activation by cyclin D1 may couple cell proliferation to energy homeostasis