Direct 3D Tomographic Reconstruction and Phase-Retrieval of Far-Field Coherent Diffraction Patterns

We present an alternative numerical reconstruction algorithm for direct tomographic reconstruction of a sample refractive indices from the measured intensities of its far-field coherent diffraction patterns. We formulate the well-known phase-retrieval problem in ptychography in a tomographic framework which allows for simultaneous reconstruction of the illumination function and the sample refractive indices in three dimensions. Our iterative reconstruction algorithm is based on the Levenberg-Marquardt algorithm. We demonstrate the performance of our proposed method with simulation studies

Developing health enhancing physical activity modules for higher and vocational education

Health enhancing physical inactivity is a growing concern leading to health problems in Europe and nationwide. WHO (2017) stated that the current levels of physical inactivity are the consequence of insufficient participation in physical activity and an increase in sedentary behavior. The British Heart Foundation (2015) also reported that 13 to 15 years in England were sedentary for six hours or more for both genders (boys = 24%, girls = 16%) on weekdays, and there was a spike of sedentary behaviour on weekend days with 43% of boys and 37% for this age group. The "Sport, Physical Education and Coaching for Health" (SPEACH) project, is an Erasmus+ Programme of the European Union (2015-2017). The key purpose of the project to prepare professional practitioners in higher and vocational education in the areas of Physical Education, Sports and Physical Activity to change behaviors of the citizens of Europe and increase physical activity. To achieve this, the project culminated in developing, validating, piloting and evaluating five Health Enhancing Physical Activity (HEPA) related modules, which may be embedded into existing education structures in the areas of Physical Education, Sports and Physical Activity. The design of the HEPA modules attempts to test a cutting edge multidisciplinary approach that bridges the gap between research / theory and practice (Armour, 2014). The needs analysis phase of the project comprised survey responses of 660 students in higher and vocational education studying Physical Education, Sports and Physical Activity from seven European countries; 14 interviewees with subject experts; and a focus group with professional and academic field experts. The results demonstrated that students in particular welcome a multidisciplinary approach for module content. The combination of “dual” content themes in modules was a key innovation that students responded favourably to, therefore HEPA modules covered themes such as changing behavior; personal leadership; physical activity for special target groups; health policy; linked to young people, their families and sport; management; nutrition, walking sports and healthy aging; and so on.. Surveyed students’ views of desirable pedagogy / didactics for these modules were practice oriented; training; internship / work based; group-and classroom based teaching. Three HEPA modules were piloted in a real-life setting in an intensive week of teaching (20 hours) each module to three groups of undergraduate students from Physical Education, Sports and Physical Activity from Europe that opted to participate in the pilot study. The developed HEPA modules were evaluated by students and staff; and the findings demonstrated relevance, enjoyment, flexibility and differentiated levels of instruction that will facilitate the embedding of any of these modules at vocational, bachelor as well as master level. These modules will be available online in an open resource that will facilitate free access, collaboration and cooperation of stakeholders in higher and vocational education in the areas of Physical Education, Sports and Physical Activity

Experimental determination of the degree of quantum polarisation of continuous variable states

We demonstrate excitation-manifold resolved polarisation characterisation of continuous-variable (CV) quantum states. In contrast to traditional characterisation of polarisation that is based on the Stokes parameters, we experimentally determine the Stokes vector of each excitation manifold separately. Only for states with a given photon number does the methods coincide. For states with an indeterminate photon number, for example Gaussian states, the employed method gives a richer and more accurate description. We apply the method both in theory and in experiment to some common states to demonstrate its advantages.Comment: 5 page

Analysis of animal serum proteins using antisera against human analogous proteins: A study of immunological cross reaction between human and animal serum proteins

In the present rocket immunoelectrophoretic analysis commercially available antisera against human serum proteins were screened for their usability in the analysis of analogous proteins in a number of animal species.The result appears as a table which demonstrates to what extent antibodies raised against a human protein can be used in the quantitative and/or qualitative study of an analogous animal protein

Experimental Demonstration of Squeezed State Quantum Averaging

We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to efficiently stabilize a set of fragile squeezed light sources with statistically fluctuating noise levels. The averaged variances are prepared probabilistically by means of linear optical interference and measurement induced conditioning. We verify that the implemented harmonic mean outperforms the standard arithmetic mean strategy. The effect of quantum averaging is experimentally tested both for uncorrelated and partially correlated noise sources with sub-Poissonian shot noise or super-Poissonian shot noise characteristics.Comment: 4 pages, 5 figure

Too much of a good thing: how ectopic DNA replication affects bacterial replication dynamics

Copyright © 2020 Syeda, Dimude, Skovgaard and Rudolph. Each cell division requires the complete and accurate duplication of the entire genome. In bacteria, the duplication process of the often-circular chromosomes is initiated at a single origin per chromosome, resulting in two replication forks that traverse the chromosome in opposite directions. DNA synthesis is completed once the two forks fuse in a region diametrically opposite the origin. In some bacteria, such as Escherichia coli, the region where forks fuse forms a specialized termination area. Polar replication fork pause sites flanking this area can pause the progression of replication forks, thereby allowing forks to enter but not to leave. Transcription of all required genes has to take place simultaneously with genome duplication. As both of these genome trafficking processes share the same template, conflicts are unavoidable. In this review, we focus on recent attempts to add additional origins into various ectopic chromosomal locations of the E. coli chromosome. As ectopic origins disturb the native replichore arrangements, the problems resulting from such perturbations can give important insights into how genome trafficking processes are coordinated and the problems that arise if this coordination is disturbed. The data from these studies highlight that head-on replication–transcription conflicts are indeed highly problematic and multiple repair pathways are required to restart replication forks arrested at obstacles. In addition, the existing data also demonstrate that the replication fork trap in E. coli imposes significant constraints to genome duplication if ectopic origins are active. We describe the current models of how replication fork fusion events can cause serious problems for genome duplication, as well as models of how such problems might be alleviated both by a number of repair pathways as well as the replication fork trap system. Considering the problems associated both with head-on replication- transcription conflicts as well as head-on replication fork fusion events might provide clues of how these genome trafficking issues have contributed to shape the distinct architecture of bacterial chromosomes.Biotechnology and Biological Sciences Research CouncilBiotechnology and Biological Sciences Research Council, research grants BB/K015729/1 and BB/N014995/1

Inference for bounded parameters

The estimation of signal frequency count in the presence of background noise has had much discussion in the recent physics literature, and Mandelkern [1] brings the central issues to the statistical community, leading in turn to extensive discussion by statisticians. The primary focus however in [1] and the accompanying discussion is on the construction of a confidence interval. We argue that the likelihood function and $p$-value function provide a comprehensive presentation of the information available from the model and the data. This is illustrated for Gaussian and Poisson models with lower bounds for the mean parameter