Econometric and Machine Learning Methods to Identify Pedestrian Crash Patterns

Walking plays an important role in overcoming many challenges nowadays, and governments and local authorities are encouraging healthy and environmentally sustainable lifestyles. Nevertheless, pedestrians are the most vulnerable road users and crashes with pedestrian involvement are a serious concern. Thus, the identification of pedestrian crash patterns is crucial to identify appropriate safety countermeasures. The aims of the study are (1) to identify the road infrastructure, environmental, vehicle, and driver-related patterns that are associated with an overrepresentation of pedestrian crashes, and (2) to identify safety countermeasures to mitigate the detected pedestrian crash patterns. The analysis carried out an econometric model, namely the mixed logit model, and the association rules and the classification tree algorithm, as machine learning tools, to analyse the patterns contributing to the overrepresentation of pedestrian crashes in Italy. The dataset consists of 874,847 crashes—including 101,032 pedestrian crashes—that occurred in Italy from 2014 to 2018. The methodological approach adopted in the study was effective in uncovering relations among road infrastructure, environmental, vehicle, and driver-related patterns, and the overrepresentation of pedestrian crashes. The mixed logit provided a clue on the impact of each pattern on the pedestrian crash occurrence, whereas the association rules and the classification tree detected the associations among the patterns with insights on how the co-occurrence of more factors could be detrimental to pedestrian safety. Drivers’ behaviour and psychophysical state turned out to be crucial patterns related to pedestrian crashes’ overrepresentation. Based on the identified crash patterns, safety countermeasures have been proposed

Studi Hubungan Substrat Dasar dan Kandungan Bahan Organik dalam Sedimen dengan Kelimpahan Hewan Makrobenthos di Muara Sungai Sayung Kabupaten Demak

Muara sungai Sayung merupakan daerah yang telah mengalami Perubahan kondisi ekologi perairan yang disebabkan karena pengaruh pasang tertinggi (rob). Daerah tersebut telah berubah menjadi daerah tergenang dan banyak didominasi oleh substrat berlumpur. Substrat lumpur kaya akan bahan organik dan akan menjadi cadangan makanan bagi hewan makrobenthos yang hidup di muara sungai. Tujuan dari penelitian ini adalah untuk mengetahui hubungan substrat dasar dan kandungan bahan organik dalam sedimen dengan kelimpahan hewan makrobenthos, dan untuk mengetahui kondisi lingkungan Muara Sungai Sayung berdasarkan nilai keanekaragaman dan keseragaman hewan makrobenthos. Penelitian ini berdasarkan studi kasus dan menggunakan metode purposive sampling untuk pengambilan sampel. Hasil penelitian dari ketiga stasiun di Muara Sungai Sayung didapatkan kelimpahan hewan makrobenthos berkisar antara 363 – 4829 ind/m3. Hewan makrobenthos yang didapatkan selama penelitian terdiri dari 3 kelas yaitu Polychaeta, Gastropoda, dan Bivalvia. Hasil penelitian pada stasiun I nilai indeks keanekaragaman sebesar 0,63, indeks keseragaman sebesar 0,57, Stasiun II nilai indeks keanekaragaman sebesar 0,13, indeks keseragaman sebesar 0,19, dan Stasiun III diperoleh nilai indeks keanekaragaman sebesar 1,79 dan indeks keseragaman sebesar 0,78. Nilai keanekaragaman tergolong dalam kategori rendah sampai sedang yang menunjukkan bahwa kondisi lingkungan sudah tidak layak untuk kehidupan hewan makrobenthos di dalamnya dan nilai keseragaman termasuk dalam kategori kecil sampai tinggi yang menunjukkan bahwa komposisi jenis hewan makrobenthos tidak sama dan kondisi ekosistemnya tidak stabil sehingga rawan akan terjadinya penurunan pada fungsi ekosistemnya. Berdasarkan nilai uji regresi sederhana dan uji regresi berganda dimana nilai koefisien korelasi berkisar 0,9 < r ≤ 1,0 menunjukkan bahwa kelimpahan hewan makrobenthos memiliki hubungan yang sangat kuat dan memiliki korelasi yang sangat nyata dengan jenis substrat dasar dan kandungan bahan organik dalam sedimen

Mixing enhancement induced by viscoelastic micromotors in microfluidic platforms

Fine manipulation of fluid flows at the microscale has a tremendous impact on mass transport phenomena of chemical and biological processes inside microfluidic platforms. Fluid mixing in the laminar flow regime at low Reynolds number is poorly effective due to the inherently slow diffusive mechanism. As a strategy to enhance mixing and prompt mass transport, here, we focus on polyelectrolyte multilayer capsules (PMCs), embodying a catalytic polyoxometalate, as microobjects to create elastic turbulence and as micromotors to generate chaotic flows by fuel-fed propulsions. The effects of the elastic turbolence and of the artificial propulsion on some basic flow parameters, such as pressure and volumetric flow rate, are studied by a microfluidic set-up including pressure and flow sensors. Numerical-handling and physical models of the experimental data are presented and discussed to explain the measured dependence of the pressure drop on the flow rate in presence of the PMCs. As a practical outcome of the study, a strong decrease of the mixing time in a serpentine microreactor is demonstrated. Unlike our previous reports dealing with capillarity flow studies, the present paper relies on hydrodynamic pumping experiments, that allow us to both develop a theoretical model for the understanding of the involved phenomena and demonstrate a successful microfluidic mixing application. All of this is relevant in the perspective of developing microobject-based methods to overcome microscale processes purely dominated by diffusion with potential improvements of mass trasport in microfluidic platforms. \ua9 2019 Elsevier B.V

Evaluation of laser-based spectrometers for greenhouse gas flux measurements in coastal marshes

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Limnology and Oceanography: Methods 14 (2016): 466–476, doi:10.1002/lom3.10105.Precise and rapid analyses of greenhouse gases (GHGs) will advance understanding of the net climatic forcing of coastal marsh ecosystems. We examined the ability of a cavity ring down spectroscopy (CRDS) analyzer (Model G2508, Picarro) to measure carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes in real-time from coastal marshes through comparisons with a Shimadzu GC-2014 (GC) in a marsh mesocosm experiment and with a similar laser-based N2O analyzer (Model N2O/CO, Los Gatos Research) in both mesocosm and field experiments. Minimum (analytical) detectable fluxes for all gases were more than one order of magnitude lower for the Picarro than the GC. In mesocosms, the Picarro analyzer detected several CO2, CH4, and N2O fluxes that the GC could not, but larger N2O fluxes (218–409 μmol m−2 h−1) were similar between analyzers. Minimum detectable fluxes for the Picarro were 1 order of magnitude higher than the Los Gatos analyzer for N2O. The Picarro and Los Gatos N2O fluxes (3–132 μmol m−2 h−1) differed in two mesocosm nitrogen addition experiments, but were similar in a mesocosm with larger N2O fluxes (326–491 μmol m−2 h−1). In a field comparison, Picarro and Los Gatos N2O fluxes (13 ± 2 μmol m−2 h−1) differed in plots receiving low nitrogen loads but were similar in plots with higher nitrogen loads and fluxes roughly double in magnitude. Both the Picarro and Los Gatos analyzers offer efficient and precise alternatives to GC-based methods, but the former uniquely enables simultaneous measurements of three major GHGs in coastal marshes.This study was funded by the USDA National Institute of Food and Agriculture (Hatch project # 229286, grant to Moseman-Valtierra) and a Woods Hole Sea Grant award to Moseman-Valtierra and Tang

Role of unenhanced breast MRI for detecting and differentiating breast lesions

N. A

Characterization and Performance of PADME's Cherenkov-Based Small-Angle Calorimeter

The PADME experiment, at the Laboratori Nazionali di Frascati (LNF), in Italy, will search for invisible decays of the hypothetical dark photon via the process $e^+e^-\rightarrow \gamma A'$, where the $A'$ escapes detection. The dark photon mass range sensitivity in a first phase will be 1 to 24 MeV. We report here on measurement and simulation studies of the performance of the Small-Angle Calorimeter, a component of PADME's detector dedicated to rejecting 2- and 3-gamma backgrounds. The crucial requirement is a timing resolution of less than 200 ps, which is satisfied by the choice of PbF$_2$ crystals and the newly released Hamamatsu R13478UV photomultiplier tubes (PMTs). We find a timing resolution of 81 ps (with double-peak separation resolution of 1.8 ns) and a single-crystal energy resolution of 5.7%/$\sqrt{E}$ with light yield of 2.07 photo-electrons per MeV, using 100 to 400 MeV electrons at the Beam Test Facility of LNF. We also propose the investigation of a two-PMT solution coupled to a single PbF$_2$ crystal for higher-energy applications, which has potentially attractive features.Comment: 12 pages, 19 figures. v2: added section on radiation damage studie

La psichiatria di consultazione e collegamento nell’ospedale generale: l’esperienza perugina

Objective - This study describes the Consultation-Liaison Service of the Perugia University and investigates the significant associations between a many variables of the assessed population. Results - During the time from July 2008 to June 2009, 722 consultations were performed at the general hospital in Perugia. First examinations were 605. Most consultations involved European patients (95,2%) of female gender (56.3%); mean age was 55.77 (SD ± 21.27). Emergencies were 22.5%; one fifth of patients were not informed of having been referred to our service and half of interventions were requested by departments of internal medicine. The primary reasons for the referral were depression (18.6%), unexplained physical symptoms (12.3%) and anxiety (10.4%); most patients were already taking psychotropic medication before our intervention (58.8%).The significant associations are the following: associations between gender and social status (p < 0.01), social condition (p < 0.01), work (p < 0.01) and advice about the need of the consultation (p < 0.05). The area (medical, surgical and specialized area) are related with the advice (p < 0.05), the reason (p < 0.01) and the type of the consultation (p < 0.01), the diagnostic explanations (p < 0.01), the liaison investigations (p < 0.01) and, at last, with the longrange plan after discharge (p < 0.01)

Role of Sterylglucosidase 1 (Sgl1) on the pathogenicity of Cryptococcus neoformans: Potential applications for vaccine development

Cryptococcosis caused by C. neoformans and C. gattii affects a large population and is a cause of significant morbidity and mortality. Despite its public health burden, there are currently no vaccines against cryptococcosis and new strategies against such infections are needed. In this study, we demonstrate that C. neoformans has the biochemical ability to metabolize sterylglucosides (SGs), a class of immunomodulatory glycolipids. Genetic manipulations that eliminate cryptococccal sterylglucosidase lead to the accumulation of SGs and generate a mutant strain (Îsgl1) that is non-pathogenic in the mouse models of cryptococcosis. Interestingly, this mutant strain acts as a vaccine strain and protects mice against cryptococcosis following infection with C. neoformans or C. gattii. The immunity induced by the Îsgl1 strain is not CD4+ T-cells dependent. Immunocompromised mice, which lack CD4+ T-cells, are able to control the infection by Îsgl1 and acquire immunity against the challenge by wild-type C. neoformans following vaccination with the Îsgl1 strain. These findings are particularly important in the context of HIV/AIDS immune deficiency and suggest that the Îsgl1 strain might provide a potential vaccination strategy against cryptococcosis

Excitonic Funneling in Extended Dendrimers with Non-Linear and Random Potentials

The mean first passage time (MFPT) for photoexcitations diffusion in a funneling potential of artificial tree-like light-harvesting antennae (phenylacetylene dendrimers with generation-dependent segment lengths) is computed. Effects of the non-linearity of the realistic funneling potential and slow random solvent fluctuations considerably slow down the center-bound diffusion beyond a temperature-dependent optimal size. Diffusion on a disordered Cayley tree with a linear potential is investigated analytically. At low temperatures we predict a phase in which the MFPT is dominated by a few paths.Comment: 4 pages, 4 figures, To be published in Phys. Rev. Let