A formula for the number of days between the winter solstice and the latest sunrise

A simple closed-form expression for the number of days between the winter solstice and the latest sunrise is derived. Formulas for the summer solstice and the sunset are derived as well. These approximate formulas make it easy to see the functional dependence on the latitude of the observer. An approximate expression for the difference in time of day between the latest sunrise and the sunrise on the solstice is also derived. The formulas are not valid in the Arctic, Antarctic or tropics.Comment: 9 pages, 1 figur

Evaluation of the activity of the immune system and age-related tissue markers in Turquoise killifish \ud (Nothobranchius furzeri, Jubb 1971) \ud and their role in cell ageing\ud

Currently the Turquoise Killifish is considered the best animal model suitable for aging research. \ud This annual fish, from south east Africa, shows an exceptionally adaptive behaviour to dry periods: indeed, due to this extreme environmental characteristics, the life cycle of Nothobranchius furzeri is very fast, with an average lifespan of just about 8-9 weeks, making this species (more similar to highly developed vertebrates than nematodes or fruit flies) highly practical for aging studies. \ud The present study has evaluated the activity of the immune system as well as the expression of AGE-RAGE system, cell-damage related proteins (Bcl2, p53), mitosis activity marker (PCNA), and pro-apoptosis activity by T.U.N.E.L. method on the liver of four lifespan-specific strains of Turquoise Killifish (Nothobranchius furzeri, Jubb 1971), correlating the results with aging processes and tumor incidence. Some groups underwent caloric restriction in order to module their expected lifespan.\ud The results demonstrated an increase of age-related lesions along with the age in all the strains tested, due to a decrease of cellular-turn-over. This aspect was also influenced by the strain of the fish: longest lifespan strains showed later the similar lesions than short lifespan strains. Moreover caloric restriction groups showed lower incidence and severity of hepatic degeneration than control groups. Furthermore, there was a linear correspondence between the age of the model and its expected lifespan with the incidence and severity of neoplasm. The same relationship could be found in the expression of cell-damage related proteins (p53, Bcl2), age-related markers (AGE-RAGE system) and pro-apoptosis activity, as well as in the development of neoplasms. These results demonstrated the high feasibility of this fish as an excellent model to study the effects of aging processes and cancer genesis.\u

Conspiracy beliefs and political violence. Empirical application of the 3N model of radicalization

In this work, I analyze conspiracy beliefs-CB and radical political reaction to them (violent protests, riots, and terrorism; see Moskalenko & McCauley, 2009) through the 3N model of radicalization (Kruglanski et al., 2009, 2014; Jasko et al., 2020), that suggest how social psychological determinants such as motivation (need for personal significance), normative influence (social network), and ideology (narrative) lead to radicalization. In two correlational and one experimental study with U.S. online samples, I tested the predictive role of collective narcissism-CN (the quest for one’s ingroup external recognition and a group level of need for significance) on support for radicalism mediation through CB. I also tested the moderation role of network ideological influence-NI on the CB- support for radicalism relationship. Study 1 (N1=547) was conducted with a sample of the general American population. The results supported the moderated mediation model proposed. The positive effect of CN on radicalism was positively mediated by CB. However, the positive effect of CB on support for radicalism was significant only in mean-high levels of NI. Study 2 (N2=574) replicates the evidence emerged in Study 1 in sample of Americans who voted for Trump in 2020 elections. Study 3 (N3=402) aims to test causal relations among the variables by manipulating CN, CB, and NI in a web-based experiment 2×2×2 experimental design through. It emerged that participants in experimental conditions (i.e., high CN high CB) showed significantly higher support for radical political participation, rather than those in any control group indicating a main effect of both on CN and CB on radicalism. However, the interaction CN×CB×NI yielded no significant evidence. These findings will be considered as framed in the psychology of terrorism and political violence, counter-radicalization, and de-radicalization

Photo-responsive oil core based polymer nanocapsules

The following PhD project regards the field of the drug delivery systems. In particular, the aim of this project is the study of chemical modifications useful to activate photo-stimuli-responsive oil core polymer nanocapsules as theranostic delivery system. Mainly, we will focus the attention on layer by layer (LbL) polymer based nanocapsules loaded with natural drugs and safe contrast agents. In the tumor treatment context, our main purpose is the use of safe nanocarriers to reduce the side effects for the patient, improving the therapy efficacy and the bioavailability of the drugs. So in this PhD project we study systems which can enhance the clinical performance and the cancer detection exploring chemical modifications in the polymeric compositions and/or in the oil core formulations. To this aim we focused the attention on highly versatile nanocapsules built around an oil core and made of completely biocompatible natural polymers employable for therapeutic and diagnostic purposes. Chemical functionalization of nanoemulsions’ shells is studied to engineer a photo-responsive nanocarrier with spatio-temporal control in the release of the drug. In Chapter 2 a LbL O/W cross-linked photo-responsive nanoemulsion, loaded with a natural drug, curcumin, is explained. As just demonstrated in our group, it is possible to functionalize the polymers deposited on the oil core, such as glycol chitosan and heparin, with a thiol moiety and an allylic moiety respectively, and then create a covalent bond between the polymeric shells via a biocompatible photoinitatior free thiol-ene ‘click’ reaction, to improve the nanosystem’s stability. Starting from this strategy to obtain a stable cross-linked LbL systems, we introduced a photolabile chemical linker, based on a modified N-acetyl cysteine-o-nitrobenzyl moiety, between the polymeric materials of LbL. Functionalized the glycol chitosan with this thiol-photo-responsive moiety and the heparin with an allyl one, we were able to perform the cross-linkage and to stabilize our LbL O/W nanoemulsion multilayer shell by the photoinitiator free thiol-ene ‘click’ reaction. Interestingly, the photo-responsive linker gave us the possibility to trigger a controlled destabilization of the nanocarriers to release the drug by single or multi-photon UV light (365 nm or 740 nm). After the chemical modifications of the nanocarriers and its characterizations in terms of stability and conditions of release, we performed biological studies of uptake and cell viability on melanoma cells. In Chapter 3 it is reported a recent published article which is part of this PhD project. It regards an oral delivery application of our nanoemulsions encapsulating nutraceutical drugs, such as curcumin and lycopene and the study of their cardioprotection and anti-inflammatory effects. These properties have been assessed by in vitro tests performed on cardiomyoblasts (H9C2 cells) in presence of doxorubicin. In Chapter 4 we report another possibility concerning the modification of the oil core formulation of the nanoemulsions, using an inorganic compound, in particular cubic iron oxide nanoparticles as contrast agents. We prepared oil-core-PEG shell nanocarriers encapsulating nanocubic iron oxide nanoparticles to study how these systems respond to in vitro photoacoustic and in vitro and in vivo magnetic resonance imaging. Final conclusion and future perspectives are presented and discussed in Chapter 5. Each part of this work can be seen distinctly or in a more general point of view. In this case, we can think to engineer a photo-responsive LbL O/W nanoemulsion co-loaded with natural drugs and safe contrast agents to employ as theranostic nanocapsules

Status of the KLOE-2 experiment

The KLOE-2 experiment at the Frascati National Laboratory of the INFN is undergoing commis- sioning, together with the e + e − collider DAΦNE. The KLOE apparatus, consisting of a huge Drift Chamber and an Electromagnetic Colorimeter working in a 0.5 T axial magnetic field, has been upgraded with the insertion of an Inner Tracker, two low-angle calorimeters (CCALT and QCALT) and low-angle taggers (LET and HET) for γγ−physics. Cosmic-ray muon and collision data are being acquired in order to optimize the sub-detectors operation in view of the new data taking campaign. The first results from the ongoing commissioning of the KLOE-2 detector will be shown

Automatic Model Based Dataset Generation for Fast and Accurate Crop and Weeds Detection

Selective weeding is one of the key challenges in the field of agriculture robotics. To accomplish this task, a farm robot should be able to accurately detect plants and to distinguish them between crop and weeds. Most of the promising state-of-the-art approaches make use of appearance-based models trained on large annotated datasets. Unfortunately, creating large agricultural datasets with pixel-level annotations is an extremely time consuming task, actually penalizing the usage of data-driven techniques. In this paper, we face this problem by proposing a novel and effective approach that aims to dramatically minimize the human intervention needed to train the detection and classification algorithms. The idea is to procedurally generate large synthetic training datasets randomizing the key features of the target environment (i.e., crop and weed species, type of soil, light conditions). More specifically, by tuning these model parameters, and exploiting a few real-world textures, it is possible to render a large amount of realistic views of an artificial agricultural scenario with no effort. The generated data can be directly used to train the model or to supplement real-world images. We validate the proposed methodology by using as testbed a modern deep learning based image segmentation architecture. We compare the classification results obtained using both real and synthetic images as training data. The reported results confirm the effectiveness and the potentiality of our approach.Comment: To appear in IEEE/RSJ IROS 201

Local symmetry in liquid metals probed by x-ray absorption spectroscopy

The nature of local point symmetry in simple monoatomic liquids has been a fundamental open question for almost 40 years of computational and experimental studies. We present original results of local ordering in different monoatomic liquids obtained by x-ray absorption spectroscopy (XAS), exploiting its high sensitivity to short-range ordering. We used Reverse Monte Carlo (RMC) analysis (RMC-GNXAS package) for obtaining structural models compatible with XAS experimental data (and diffraction techniques for long-range ordering). Pair, bond-angle distributions and suitable indicators for point symmetry are calculated for different liquid metals

Saturation phenomena for ultra short Free Electron Laser pulses

Saturable absorption was recently observed in transmission measurements above the LII,III edge of pure Al thin films using ultra short x-ray pulses at a free-electron-laser (FEL) facility . [1] The high fluence reachable by FEL pulses, the shortness of the pulse duration, and the typical lifetime of the excited state, are all important factors enabling observation of the phenomenon. We devised a simplified theoretical model describing the saturation phenomenon using a three- channel model containing ground, excited and relaxed states. This phenomenological model explicitly includes the interaction between the solid and photon field in semi cl assical way, and the resulting non-linear coupled equation is solved numerically. We successfully applied this model to recent experimental results obtained using FEL radiation. [2,3