Izloženost genotoksičnim agensima iz životnog okoliša tijekom prenatalnog razvoja i djetinjstva

Health disorders and diseases related to environmental exposure in children such as cancer and immunologic disturbances (asthma, allergies) are on the rise. However, complex transplacental and prepubertal genotoxicology is given very limited consideration, even though intrauterine development and early childhood may be critical for elucidating the cancer aetiology. The foetus is transplacentally exposed to contaminants in food and environment such as various chemicals, drugs, radiochemically contaminated water and air. Target organs of xenobiotic action may differ between the mother and the foetus due to specific stage of developmental physiology and enzyme distribution. This in turn may lead to different levels of clastogenic and aneugenic metabolites of the same xenobiotic in the mother and the foetus. Adult’s protective behaviour is not sufficient to isolate children from radioisotopes, pesticides, toxic metals and metalloids, environmental tobacco smoke, endocrine disrupting chemicals, and various food contaminants, which are just a part of the stressors present in a polluted environment. In order to improve legislation related to foetus and child exposure to genotoxic and possibly carcinogenic agents, oncologists, paediatricians, environmental health specialists, and genotoxicologists should work together much more closely to make a more effective use of accumulated scientific data, with the final aim to lower cancer incidence and mortality.Unatoč velikim naporima da se smanji okolišna izloženost u djece se dalje bilježi trend porasta pojavnosti karcinoma i imunosnih poremećaja (astma, alergije). Premda su intrauterini razvoj i rano djetinjstvo kritično razdoblje za tumačenje etiologije nastanka karcinoma, transplacentalna i prepubertetna genotoksikologija do danas su slabo istražene. Fetus je transplacentalno izložen brojnim fizikalnim i kemijskim čimbenicima: kontaminantima iz hrane i okoliša, radiokemijski kontaminiranoj vodi, zraku te lijekovima. Ciljna tkiva za djelovanje ksenobiotika mogu biti različita u majke i fetusa zbog različitosti u razvojnoj fiziologiji i distribuciji enzima. Zbog toga u organizmu majke i fetusa mogu nastati različite razine klastogenih i aneugenih metabolita istog ksenobiotika. Zaštitna uloga odraslih u namjeri da spriječe negativne utjecaje onečišćenog okoliša na djetetovo zdravlje često je ograničena jer su radioizotopi, olovo, PCB, pasivno pušenje, živa, endokrino aktivne tvari, pesticidi i kontaminanti prisutni u svim životnim područjima tijekom razvoja i rasta djeteta. Kako bi se poboljšalo zakonodavstvo vezano uz izloženost djece genotoksičnim i vjerojatno kancerogenim tvarima, tijekom razvoja potrebna je bolja suradnja onkologa, pedijatara, stručnjaka zdravstvene ekologije i genotoksikologa. Na taj način ostvarilo bi se uspješnije iskorištavanje postojećih znanstvenih podataka u cilju smanjenja incidencije karcinoma i mortaliteta

LHCb upgrade software and computing : technical design report

This document reports the Research and Development activities that are carried out in the software and computing domains in view of the upgrade of the LHCb experiment. The implementation of a full software trigger implies major changes in the core software framework, in the event data model, and in the reconstruction algorithms. The increase of the data volumes for both real and simulated datasets requires a corresponding scaling of the distributed computing infrastructure. An implementation plan in both domains is presented, together with a risk assessment analysis

Physics case for an LHCb Upgrade II - Opportunities in flavour physics, and beyond, in the HL-LHC era

The LHCb Upgrade II will fully exploit the flavour-physics opportunities of the HL-LHC, and study additional physics topics that take advantage of the forward acceptance of the LHCb spectrometer. The LHCb Upgrade I will begin operation in 2020. Consolidation will occur, and modest enhancements of the Upgrade I detector will be installed, in Long Shutdown 3 of the LHC (2025) and these are discussed here. The main Upgrade II detector will be installed in long shutdown 4 of the LHC (2030) and will build on the strengths of the current LHCb experiment and the Upgrade I. It will operate at a luminosity up to 2×1034 cm−2s−1, ten times that of the Upgrade I detector. New detector components will improve the intrinsic performance of the experiment in certain key areas. An Expression Of Interest proposing Upgrade II was submitted in February 2017. The physics case for the Upgrade II is presented here in more depth. CP-violating phases will be measured with precisions unattainable at any other envisaged facility. The experiment will probe b → sl+l−and b → dl+l− transitions in both muon and electron decays in modes not accessible at Upgrade I. Minimal flavour violation will be tested with a precision measurement of the ratio of B(B0 → μ+μ−)/B(Bs → μ+μ−). Probing charm CP violation at the 10−5 level may result in its long sought discovery. Major advances in hadron spectroscopy will be possible, which will be powerful probes of low energy QCD. Upgrade II potentially will have the highest sensitivity of all the LHC experiments on the Higgs to charm-quark couplings. Generically, the new physics mass scale probed, for fixed couplings, will almost double compared with the pre-HL-LHC era; this extended reach for flavour physics is similar to that which would be achieved by the HE-LHC proposal for the energy frontier

Observation of the Doubly Charmed Baryon Xi(++)(cc)

International audienceA highly significant structure is observed in the Λc+K-π+π+ mass spectrum, where the Λc+ baryon is reconstructed in the decay mode pK-π+. The structure is consistent with originating from a weakly decaying particle, identified as the doubly charmed baryon Ξcc++. The difference between the masses of the Ξcc++ and Λc+ states is measured to be 1334.94±0.72(stat.)±0.27(syst.)  MeV/c2, and the Ξcc++ mass is then determined to be 3621.40±0.72(stat.)±0.27(syst.)±0.14(Λc+)  MeV/c2, where the last uncertainty is due to the limited knowledge of the Λc+ mass. The state is observed in a sample of proton-proton collision data collected by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.7  fb-1, and confirmed in an additional sample of data collected at 8 TeV

Measurement of branching fractions of charmless four-body Λ⁰_b and Ξ⁰_b decays

A search for charmless four-body decays of Λ b 0 and Ξ b 0 baryons with a proton and three charged mesons (either kaons or pions) in the final state is performed. The data sample used was recorded in 2011 and 2012 with the LHCb experiment and corresponds to an integrated luminosity of 3 fb−1. Six decay modes are observed, among which Λ b 0  → pK−π+π−, Λ b 0  → pK−K+K−, Ξ b 0  → pK−π+π− and Ξ b 0  → pK−π+K− are established for the first time. Their branching fractions (including the ratio of hadronisation fractions in the case of the Ξ b 0 baryon) are determined relative to the Λ b 0  → Λ c + π− decay

Measurement of the B0s→μ+μ− Branching Fraction and Effective Lifetime and Search for B0→μ+μ− Decays

A search for the rare decays Bs0→μ+μ- and B0→μ+μ- is performed at the LHCb experiment using data collected in pp collisions corresponding to a total integrated luminosity of 4.4  fb-1. An excess of Bs0→μ+μ- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0→μ+μ-)=(3.0±0.6-0.2+0.3)×10-9, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0→μ+μ- effective lifetime, τ(Bs0→μ+μ-)=2.04±0.44±0.05  ps, is reported. No significant excess of B0→μ+μ- decays is found, and a 95% confidence level upper limit, B(B0→μ+μ-)<3.4×10-10, is determined. All results are in agreement with the standard model expectations.A search for the rare decays $B^0_s\to\mu^+\mu^-$ and $B^0\to\mu^+\mu^-$ is performed at the LHCb experiment using data collected in $pp$ collisions corresponding to a total integrated luminosity of 4.4 fb$^{-1}$. An excess of $B^0_s\to\mu^+\mu^-$ decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be ${\cal B}(B^0_s\to\mu^+\mu^-)=\left(3.0\pm 0.6^{+0.3}_{-0.2}\right)\times 10^{-9}$, where the first uncertainty is statistical and the second systematic. The first measurement of the $B^0_s\to\mu^+\mu^-$ effective lifetime, $\tau(B^0_s\to\mu^+\mu^-)=2.04\pm 0.44\pm 0.05$ ps, is reported. No significant excess of $B^0\to\mu^+\mu^-$ decays is found and a 95 % confidence level upper limit, ${\cal B}(B^0\to\mu^+\mu^-)<3.4\times 10^{-10}$, is determined. All results are in agreement with the Standard Model expectations

Measurement of the charged cosmic ray flux at solar minimum with the PERDaix detector

This thesis deals with the development and data analysis of the PERDaix detector (Proton Electron Radiation Detector Aix-la-Chapelle). PERDaix is a particle detector with an geometrical acceptance of 33 cm2sr designed to measure the charged cosmic-ray flux with the help of three subdetectors: a spectrometer consisting of a permanentmagnet and eight tracker layers, a time-of-flight detector (TOF), and a transition radiation detector (TRD). The detector was flown on board a stratospheric research balloon in November 2010. It recorded about 170 000 events during the 1.5 hour long float phase at an altitude of 33 km. These data allow the measurement of the primarycosmic-ray flux of protons and helium nuclei.PERDaix uses novel detector technologies for a precise measurement of charged particles. These technologies are based on the light emitted when a charged particle crosses a so-called scintillation material. This scintillation light is detected with SiPMs – highly sensitive semiconductor photo detectors developed during the last few years. They achieve a detection efficiency of up to 50 % and an internal gain of the order of 106 . These properties allow the detection of single photons without the need for a sophisticated low-noise amplification circuit. Several SiPMs can be produced next to each other on a silicon substrate to form a linear array. The possibility of a fine segmentation (250 μm) make them suitable for high resolution tracking detectors. The scintillation light is produced in a ribbon of five layers of 250 μm thin fibers. This thesis shows that the production process yields tracker modules with a very homogeneous response and a single point resolution of 50 μm. SiPMs are also used in the TOF to read out 5 cm wide scintillator bars. The TOF provides the main trigger for the other subdetectors, the differentiation of up- fromdownward flying particles, the information for the particle identification via the signal heights, and an improvement of momentum resolution at low energies. The development, test measurements, and performance of the TOF are presented. The TOF reaches a time difference resolution of 420 ps with an efficiency close to one.The thesis shows the design concepts, the special challenges of the operation on board a stratospheric research balloon, and data analysis concepts which finally end in measured cosmic-ray fluxes of protons and helium nuclei. These are used to determine the solar modulation parameter in November 2010

Measurement of the charged cosmic ray flux at solar minimum with the PERDaix detector

This thesis deals with the development and data analysis of the PERDaix detector (Proton Electron Radiation Detector Aix-la-Chapelle). PERDaix is a particle detector with an geometrical acceptance of 33 cm2sr designed to measure the charged cosmic-ray flux with the help of three subdetectors: a spectrometer consisting of a permanentmagnet and eight tracker layers, a time-of-flight detector (TOF), and a transition radiation detector (TRD). The detector was flown on board a stratospheric research balloon in November 2010. It recorded about 170 000 events during the 1.5 hour long float phase at an altitude of 33 km. These data allow the measurement of the primarycosmic-ray flux of protons and helium nuclei.PERDaix uses novel detector technologies for a precise measurement of charged particles. These technologies are based on the light emitted when a charged particle crosses a so-called scintillation material. This scintillation light is detected with SiPMs – highly sensitive semiconductor photo detectors developed during the last few years. They achieve a detection efficiency of up to 50 % and an internal gain of the order of 106 . These properties allow the detection of single photons without the need for a sophisticated low-noise amplification circuit. Several SiPMs can be produced next to each other on a silicon substrate to form a linear array. The possibility of a fine segmentation (250 μm) make them suitable for high resolution tracking detectors. The scintillation light is produced in a ribbon of five layers of 250 μm thin fibers. This thesis shows that the production process yields tracker modules with a very homogeneous response and a single point resolution of 50 μm. SiPMs are also used in the TOF to read out 5 cm wide scintillator bars. The TOF provides the main trigger for the other subdetectors, the differentiation of up- fromdownward flying particles, the information for the particle identification via the signal heights, and an improvement of momentum resolution at low energies. The development, test measurements, and performance of the TOF are presented. The TOF reaches a time difference resolution of 420 ps with an efficiency close to one.The thesis shows the design concepts, the special challenges of the operation on board a stratospheric research balloon, and data analysis concepts which finally end in measured cosmic-ray fluxes of protons and helium nuclei. These are used to determine the solar modulation parameter in November 2010