Improving parametric neural networks for high-energy physics (and beyond)

Signal-background classification is a central problem in high-energy physics, that plays a major role for the discovery of new fundamental particles. A recent method-the parametric neural network (pNN)-leverages multiple signal mass hypotheses as an additional input feature to effectively replace a whole set of individual classifiers, each providing (in principle) the best response for the corresponding mass hypothesis. In this work we aim at deepening the understanding of pNNs in light of real-world usage. We discovered several peculiarities of parametric networks, providing intuition, metrics, and guidelines to them. We further propose an alternative parametrization scheme, resulting in a new parametrized neural network architecture: the AffinePNN; along with many other generally applicable improvements, like the balanced training procedure. Finally, we extensively and empirically evaluate our models on the HEPMASS dataset, along its imbalanced version (called HEPMASS-IMB) we provide here for the first time, to further validate our approach. Provided results are in terms of the impact of the proposed design decisions, classification performance, and interpolation capability, as well

Investigation of Deterioration of Joints in Concrete Pavements: Field Study of Penetrating Sealers

The objective of this research was to assess the efficacy of various waterproofing sealers applied to pavement joints with respect to limiting water ingress. The measure of water ingress was the chloride concentration profile as measured by scanning electron microscopy and energy dispersive spectroscopy. The fieldwork was conducted at the MnROAD facility. Cores were retrieved from pavements to assess the before condition. Various silane- and siloxane-based sealers were applied in 2013, and the pavements were exposed to service for two years. After two years, cores were retrieved. The chloride profiles for various pavement sites were compared before and after application of the sealer. No appreciable differences were noted. The lack of measured differences is attributed to the short time span allowed for ingress. The older pavements measured had a considerable degree of chloride ingress and, as such, small changes were difficult to detect. The newer pavement analyzed also showed no appreciable change, but it would be worth re-analyzing after more time has elapsed (e.g., two more years)

Monitoring the microtubule nucleation dynamics of sperm centriole after IFV and ICSI in sheep zygotes.

Intracytoplasmic sperm injection (ICSI) is an assisted reproductive (ART) technique that is less efficient in ruminant, comparing to other species. In mammals, the spermatozoa proximal centriole nucleates the microtubule and generates the functional cell centriole of the resulting organism. Our study aimed to investigate eventual difference in the centriole microtubular nucleation in ICSI fertilized oocytes, comparing to control In Vitro Fertilized ones (IVF). In fact, we made the hypothesis that the tail severing step achieved in our ICSI protocol through applying a few piezo pulses, might mechanically damage the proximal centriole. On this basis, Sheep oocytes were in vitro maturated (IVM) for 24 h then were injected by piezo-pulsed spermatozoa, chemically activated by 5 min of incubation with 5 mg/ml ionomycin, washed in H199 for 5 min and cultured in 50 µl drops of Synthetic Oviductal Fluid (SOF) with estrus sheep serum and 16 µM isoproterenol, covered by mineral oil. Fertilization has been arrested around 5h after ICSI, and the presumptive zygotes were processed for immunological detection of tubulin. Zona Pellucida (ZP) was removed with a combined treatment of acid Tyrode and trypsin and zygotes were then fixed with 4% paraformaldehyde (pH7.2) and permeabilized by 0.5% Triton X-100, for 20 min each. Microtubular nucleation was assessed with anti-α-tubulin immunofluorescence under confocal microscopy. No difference was noticed in the dynamics and timing of sperm microtubular aster nucleation, that started around 5h post ICSI (5h30). Therefore, we conclude that abnormal microtubular nucleation by the centriole is not responsible for the low development of ICSI fertilized sheep oocytes

The impaired development of sheep ICSI derived embryos is not related to centriole dysfunction

While intracytoplasmic sperm injection (ICSI) is an asset in human Assisted Reproduction Technologies (ART), its outcomes, in terms of blastocyst, is still unacceptably low in ruminants. The picture typically found in ICSI derived bovine and ovine embryos is an asymmetry between a high activation rate, marked by a pronuclear development, and a low first cleavage rate. Abnormal centriole function has been indicated as a possible factor which undermines embryonic development following ICSI, especially when Freeze Dried spermatozoa (FD) are used. In order to verify the hypothesis that centriole dysfunction might be responsible for low ICSI outcomes in sheep, we have investigated micro-tubular dynamics, markedly aster nucleation, in fertilized sheep zygotes by ICSI with frozen/thawed (FT) and FD spermatozoa; In Vitro Fertilized (IVF) sheep oocytes were used as control. The spermatozoa aster nucleation was assessed at different time points following ICSI and IVF by immune-detection of α-tubulin. Pronuclear stage, syngamy and embryo development were assessed. No difference was noticed in the timing of aster nucleation and microtubule elongation in ICSI-FT derived embryos with control IVF ones, while a delay was recorded in ICSI-FD ones. The proportion of 2-pronuclear stage zygotes was similar in ICSI-FT and ICSI-FD (47% and 53%, respectively), both much lower comparing the IVF ones (73%). Likewise, syngamy was observed in a minority of both ICSI groups (28.5% vs 12.5% in ICSI-FT/FD respectively) comparing to IVF controls (50%), with a high number of zygotes blocked at the 2-pronuclear stage (71.5% vs 87.5% respectively). While no significant differences were noticed in the cleavage rate between ICSI-FD, ICSI-FT and IVF groups (31%, 34% and 44%) respectively, development to blastocyst stage was markedly compromised in both ICSI groups, especially with FD spermatozoa (10% in ICIS-FD and 19% in ICSI-FT vs 33% in IVF (P < 0.005, ICSI-FD vs IVF and P < 0.05, IVF vs ICSI-FT, respectively). Hence, here we have demonstrated that the reduced cleavage, and the ensuing impaired development to blastocysts stage of ICSI derived sheep embryos is not related to centriole dysfunction, as suggested by other authors. The major recorded problem is the lack of syngamy in ICSI derived zygotes, an issue that should be addressed in further studies to improve ICSI procedure in sheep embryos

L’ambiente marino costiero: aspetti e tutela. Progetto formativo di Alternanza Scuola Lavoro 2016‐2019 Liceo Scienze Applicate

Il percorso formativo consente di acquisire nozioni teoriche e pratiche sulle moderne tecniche (strumentali e metodologiche) di investigazione del “datum” geologico finalizzate allo studio multidisciplinare dell’ambiente marino‐costiero, con particolare riguardo alle ricerche sperimentali che l’Istituto IAMC ha condotto e conduce nel Golfo di Napoli. Vengono trattate anche tematiche di gestione del sistema sicurezza e qualità con particolare riguardo alle attività lavorative di ricerca (acquisizione, elaborazione e restituzione del dato),nonché indicazioni di procedure gestionali di progetto finalizzate al corretto utilizzo della risorsa umana e strumentale

Controlled spermatozoa–oocyte interaction improves embryo quality in sheep

The current protocols of in vitro fertilization and culture in sheep rely on paradigms established more than 25 years ago, where Metaphase II oocytes are co-incubated with capacitated spermatozoa overnight. While this approach maximizes the number of fertilized oocytes, on the other side it exposes them to high concentration of reactive oxygen species (ROS) generated by active and degenerating spermatozoa, and positively correlates with polyspermy. Here we set up to precisely define the time frame during which spermatozoa effectively penetrates and fertilizes the oocyte, in order to drastically reduce spermatozoa-oocyte interaction. To do that, in vitro matured sheep oocytes co-incubated with spermatozoa in IVF medium were sampled every 30 min (start of incubation time 0) to verify the presence of a fertilizing spermatozoon. Having defined the fertilization time frame (4 h, data from 105 oocytes), we next compared the standard IVF procedures overnight (about 16 h spermatozoa/oocyte exposure, group o/nIVF) with a short one (4 h, group shIVF). A lower polyspermic fertilization (> 2PN) was detected in shIVF (6.5%) compared to o/nIVF (17.8%), P < 0.05. The o/nIVF group resulted in a significantly lower 2-cell stage embryos, than shIVF [34.6% (81/234) vs 50.6% (122/241) respectively, P < 0.001]. Likewise, the development to blastocyst stage confirmed a better quality [29% (70/241) vs 23.5% (55/234), shIVF vs o/nIVF respectively] and an increased Total Cell Number (TCN) in shIVF embryos, compared with o/n ones. The data on ROS have confirmed that its generation is IVF time-dependent, with high levels in the o/nIVF group. Overall, the data suggest that a shorter oocyte-spermatozoa incubation results in an improved embryo production and a better embryo quality, very likely as a consequence of a shorter exposure to the free oxygen radicals and the ensuing oxidative stress imposed by overnight culture

Dry biobanking as a conservation tool in the Anthropocene

Species are going extinct at an alarming rate, termed by some as the sixth mass extinction event in the history of Earth. Many are the causes for this but in the end, all converge to one entity – humans. Since we are the cause, we also hold the key to making the change. Any change, however, will take time, and for some species this could be too long. While working on possible solutions, we also have the responsibility to buy time for those species on the verge of extinction. Genome resource banks, in the form of cryobanks, where samples are maintained under liquid nitrogen, are already in existence but they come with a host of drawbacks. Biomimicry – innovation inspired by Nature, has been a huge source for ideas. Searching methods that Nature utilizes to preserve biological systems for extended periods of time, we realize that drying rather than freezing is the method of choice. We thus argue here in favor of preserving at least part of the samples from critically endangered species in dry biobanks, a much safer, cost-effective, biobanking approach

Determination of the photodisintegration reaction rates involving charged particles: systematical calculations and proposed measurements based on Extreme Light Infrastructure - Nuclear Physics (ELI-NP)

Photodisintegration reaction rates involving charged particles are of relevance to the p-process nucleosynthesis that aims at explaining the production of the stable neutron-deficient nuclides heavier than iron. In this study, the cross sections and astrophysical rates of (g,p) and (g,a) reactions for about 3000 target nuclei with 10<Z<100 ranging from stable to proton dripline nuclei are computed. To study the sensitivity of the calculations to the optical model potentials (OMPs), both the phenomenological Woods-Saxon and the microscopic folding OMPs are taken into account. The systematic comparisons show that the reaction rates, especially for the (g,a) reaction, are dramatically influenced by the OMPs. Thus the better determination of the OMP is crucial to reduce the uncertainties of the photodisintegration reaction rates involving charged particles. Meanwhile, a gamma-beam facility at ELI-NP is being developed, which will open new opportunities to experimentally study the photodisintegration reactions of astrophysics interest. Considering both the important reactions identified by the nucleosynthesis studies and the purpose of complementing the experimental results for the reactions involving p-nuclei, the measurements of six (g,p) and eight (g,a) reactions based on the gamma-beam facility at ELI-NP and the ELISSA detector for the charged particles detection are proposed, and the GEANT4 simulations are correspondingly performed. The minimum required energies of the gamma-beam to measure these reactions are estimated. It is shown that the direct measurements of these photonuclear reactions within the Gamow windows at T_9=2.5 for p-process are fairly feasible and promising at ELI-NP. The expected experimental results will be used to constrain the OMPs of the charged particles, which can eventually reduce the uncertainties of the reaction rates for the p-process nucleosynthesis.Comment: 14 pages, 8 figures, Phys. Rev. C accepte

Three-α particle correlations in quasi-projectile decay in 12C + 24Mg collisions at 35AMeV

Two and multi particle correlations have been studied in peripheral 12C+24Mg collisions at 35AMeV with CHIMERA 4π multi detector, in order to explore resonances produced in light nuclei. Correlations techniques have become a tool to explore nuclear structure properties but also to evaluate the competition between simultaneous and sequential channels in decay of light isotopes. The exploration of features such as branching ratios with respect to different decay channels (sequential vs. simultaneous) could provide information on in-medium effects on nuclear structure properties, an important perspective for research on the nuclear interaction. The performed experiment is preliminary to further studies to be performed by coupling of CHIMERA to FARCOS (Femtoscope ARray for COrrelations and Spectroscopy, FARCOS TDR available at https://drive.google.com/file/d/0B5CgGWz8LpOOc3pGTWdOcDBoWFE) array devoted to measurements of two and multi particle correlations with high energy and angular resolutions

Whole genome integrity and enhanced developmental potential in ram freeze-dried spermatozoa at mild sub-zero temperature

Freeze-dried spermatozoa typically shows a reduction in fertility primarily due to the DNA damage resulting from the sublimation process. In order to minimize the physical/mechanical damage resulting from lyophilization, here we focused on the freezing phase, comparing two cooling protocols: (i) rapid-freezing, where ram sperm sample is directly plunged into liquid nitrogen (LN-group), as currently done; (ii) slow-freezing, where the sample is progressively cooled to − 50&nbsp;°C (SF-group). The spermatozoa dried in both conditions were analysed to assess residual water content by Thermal Gravimetric Analysis (TGA) and DNA integrity using Sperm Chromatin Structure Assay (SCSA). TGA revealed more than 90% of water subtraction in both groups. A minor DNA damage, Double-Strand Break (DSB) in particular, characterized by a lower degree of abnormal chromatin structure (Alpha-T), was detected in the SF-group, comparing to the LN-one. In accordance with the structural and DNA integrity data, spermatozoa from SF-group had the best embryonic development rates, comparing to LN-group: cleaved embryos [42/100 (42%) versus 19/75 (25.3%), P &lt; 0.05, SL and LN respectively] and blastocyst formation [7/100 (7%) versus 2/75 (2.7%), P &lt; 0.05, SF and LN respectively]. This data represents a significant technological advancement for the development of lyophilization as a valuable and cheaper alternative to deep-freezing in LN for ram semen