Measurement of the Higgs Spin and Parity in the Four-Lepton Channel with the ATLAS Detector

Honors (Bachelor's)PhysicsUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/107730/1/khegazy.pd

Boosting for Generic 2D/3D Object Recognition

Generic object recognition is an important function of the human visual system. For an artificial vision system to be able to emulate the human perception abilities, it should also be able to perform generic object recognition. In this thesis, we address the generic object recognition problem and present different approaches and models which tackle different aspects of this difficult problem. First, we present a model for generic 2D object recognition from complex 2D images. The model exploits only appearance-based information, in the form of a combination of texture and color cues, for binary classification of 2D object classes. Learning is accomplished in a weakly supervised manner using Boosting. However, we live in a 3D world and the ability to recognize 3D objects is very important for any vision system. Therefore, we present a model for generic recognition of 3D objects from range images. Our model makes use of a combination of simple local shape descriptors extracted from range images for recognizing 3D object categories, as shape is an important information provided by range images. Moreover, we present a novel dataset for generic object recognition that provides 2D and range images about different object classes using a Time-of-Flight (ToF) camera. As the surrounding world contains thousands of different object categories, recognizing many different object classes is important as well. Therefore, we extend our generic 3D object recognition model to deal with the multi-class learning and recognition task. Moreover, we extend the multi-class recognition model by introducing a novel model which uses a combination of appearance-based information extracted from 2D images and range-based (shape) information extracted from range images for multi-class generic 3D object recognition and promising results are obtained

Impact of a Disaster Educational Program on Knowledge and Practices of Teachers among Primary Governmental Schools, Cairo Governorate

Disaster is an extreme event that causes loss of life, property, essential services and means of livelihood. Aim of this study; was to assess the impact of a disaster educational program on knowledge and practices of teachers. Research design; A (pre-post) quasi-experimental design was adopted in this research. Setting; the study was conducted at three primary governmental schools in Cairo governorate. Three educational departments were assigned randomly from total thirty two departments. One school from each educational department was selected randomly (3 schools). These schools were El-Sayida Sakina, Ahmed Lotfy El-Said and El-Kasr Elaini primary governmental schools. The study sample; consisted of 50 teachers were included from three selected school in the research. Teachers number was; 17 teachers in El-Sayida Sakina School, 18 teachers in Ahmed Lotfy El-Said school and 15 in El-Kasr Elaini. Tools for data collection; three tools were used in this study; 1) Demographic characteristics for teachers; 2) Pre/ post knowledge questionnaire sheet. 3) Pre/post observational checklist. Study results; results revealed that, 70 % of teachers were females, 54% aged from 35-55 years.  Nearly all teachers (94%) didn't have any experience in disaster management before the educational program compared to less than half (42%) of the teachers who had unsatisfactory knowledge about disaster management. While 96%, 100% respectively had good knowledge scores about disaster management immediately and 2 months after the educational program. Regarding to teacher's practices, 100% and 84% had good practice scores immediately and 2 months after the educational program respectively while 90% had unsatisfactory practice scores about disaster management before the educational program. A highly statistically significance differences were found between all practice subscales about dealing with injured personnel in disaster among teachers before, immediately and 2 months after the educational program.  The study concluded that, educational program implicated changes in teaches' knowledge, and practices regarding disaster management in primary governmental schools. The study recommended periodic training programs for teachers in primary governmental schools Key words: Teachers, disaster management, primary governmental school

Investigating dissociation pathways of nitrobenzene via mega-electron-volt ultrafast electron diffraction

As the simplest nitroaromatic compound, nitrobenzene is an interesting model system to explore the rich photochemistry of nitroaromatic compounds. Previous measurements of nitrobenzene's photochemical dynamics have probed structural and electronic properties, which, at times, paint a convoluted and sometimes contradictory description of the photochemical landscape. A sub-picosecond structural probe can complement previous electronic measurements and aid in determining the photochemical dynamics with less ambiguity. We investigate the ultrafast dynamics of nitrobenzene triggered by photoexcitation at 267 nm employing megaelectronvolt ultrafast electron diffraction with femtosecond time resolution. We measure the first 5 ps of dynamics and, by comparing our measured results to simulation, we unambiguously distinguish the lowest singlet and triplet electronic states. We observe ground state recovery within 160 +/- 60 fs through internal conversions and without signal corresponding to photofragmentation. Our lack of dissociation signal within the first 5 ps indicates that previously observed photofragmenation reactions take place in the vibrationally "hot" ground state on timescales considerably beyond 5 ps.Comment: 5 pages, 3 figures, and 1 tabl

Bayesian inferencing and deterministic anisotropy for the retrieval of the molecular geometry ∣Ψ(r)∣2|\Psi(\mathbf{r})|^2 in gas-phase diffraction experiments

Currently, our general approach to retrieve the molecular geometry from ultrafast gas-phase diffraction heavily relies on complex geometric simulations to make conclusive interpretations. In this manuscript, we develop a broadly applicable ultrafast gas-phase diffraction method that approximates the molecular frame geometry $|\Psi(\mathbf{r}, t)|^2$ distribution using Bayesian Inferencing. This method does not require complex molecular dynamics simulation and can identify the unique molecular structure. We demonstrate this method's viability by retrieving the ground state geometry distribution $|\Psi(\mathbf{r})|^2$ for both simulated stretched NO$_2$ and measured ground state N$_2$O. Due to our statistical interpretation, we retrieve a coordinate-space resolution on the order of 100~fm, depending on signal quality, an improvement of order 100 compared to commonly used Fourier transform based methods. By directly measuring the width of $|\Psi(\mathbf{r})|^2$, this is generally only accessible through simulation, we open ultrafast gas-phase diffraction capabilities to measurements beyond current analysis approaches. Our method also leverages deterministic ensemble anisotropy; this provides an explicit dependence on the molecular frame angles. This method's ability to retrieve the unique molecular structure with high resolution, and without complex simulations, provides the potential to effectively turn gas-phase ultrafast diffraction into a discovery oriented technique, one that probes systems that are prohibitively difficult to simulate.Comment: 16 pages, 8 figures, 2 tables. Please find the analysis code and templates for new molecules at https://github.com/khegazy/BIG

Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules

Observing the motion of the nuclear wave packets during a molecular reaction, in both space and time, is crucial for understanding and controlling the outcome of photoinduced chemical reactions. We have imaged the motion of a vibrational wave packet in isolated iodine molecules using ultrafast electron diffraction with relativistic electrons. The time-varying interatomic distance was measured with a precision 0.07 Å and temporal resolution of 230 fs full width at half maximum. The method is not only sensitive to the position but also the shape of the nuclear wave packet

Spectroscopic and Structural Probing of Excited-State Molecular Dynamics with Time-Resolved Photoelectron Spectroscopy and Ultrafast Electron Diffraction

Pump-probe measurements aim to capture the motion of electrons and nuclei on their natural timescales (femtoseconds to attoseconds) as chemical and physical transformations take place, effectively making molecular movies with short light pulses. However, the quantum dynamics of interest are filtered by the coordinate-dependent matrix elements of the chosen experimental observable. Thus, it is only through a combination of experimental measurements and theoretical calculations that one can gain insight into the internal dynamics. Here, we report on a combination of structural (relativistic ultrafast electron diffraction, or UED) and spectroscopic (time-resolved photoelectron spectroscopy, or TRPES) measurements to follow the coupled electronic and nuclear dynamics involved in the internal conversion and photodissociation of the polyatomic molecule, diiodomethane (CH2I2). While UED directly probes the 3D nuclear dynamics, TRPES only serves as an indirect probe of nuclear dynamics via Franck-Condon factors, but it is sensitive to electronic energies and configurations, via Koopmans\u27 correlations and photoelectron angular distributions. These two measurements are interpreted with trajectory surface hopping calculations, which are capable of simulating the observables for both measurements from the same dynamics calculations. The measurements highlight the nonlocal dynamics captured by different groups of trajectories in the calculations. For the first time, both UED and TRPES are combined with theory capable of calculating the observables in both cases, yielding a direct view of the structural and nonadiabatic dynamics involved

Imaging CF\u3csub\u3e3\u3c/sub\u3eI conical intersection and photodissociation dynamics with ultrafast electron diffraction

Conical intersections play a critical role in excited-state dynamics of polyatomic molecules because they govern the reaction pathways of many nonadiabatic processes. However, ultrafast probes have lacked sufficient spatial resolution to image wave-packet trajectories through these intersections directly. Here, we present the simultaneous experimental characterization of one-photon and two-photon excitation channels in isolated CF3I molecules using ultrafast gas-phase electron diffraction. In the two-photon channel, we have mapped out the real-space trajectories of a coherent nuclear wave packet, which bifurcates onto two potential energy surfaces when passing through a conical intersection. In the one-photon channel, we have resolved excitation of both the umbrella and the breathing vibrational modes in the CF3 fragment in multiple nuclear dimensions. These findings benchmark and validate ab initio nonadiabatic dynamics calculations. Includes supplementary materials. Movie S1 attached below

Imaging the ring opening reaction of 1,3-cyclohexadiene with MeV ultrafast electron diffraction

We resolve the structural dynamics of the ultrafast photoinduced ring opening reaction of 1,3-cyclohexadiene in space and time employing megaelectronvolt gas phase ultrafast electron diffraction. We, furthermore, observe coherent large amplitude motions of the photoproduct

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London