The Aging Sperm: Is the Male Reproductive Capacity Ticking to Biological Extinction?

In other to provide some insight into the issue of male fertility with aging, several experimental, clinical and cross‑sectional epidemiological studies have been undertaken to characterize the relationship between paternal ages as a marker of the semen quality and male fertility status. The present review summarizes, comprehensively, the mechanisms that tend to relate male aging and semen quality with their consequences on semen parameters. Review of English language‑published research articles from 1980, through 2013 was executed using Medline and Medscape databases. It was found that the semen volume, concentration and vitality of spermatozoa declined significantly with age. Deoxyribonucleic acid (DNA) fragmentations, as well as abnormalities of sex chromosomes, were also reported as having a significant association with men’s age which may be one of the reasons for failure in some traditional in vitro fertilization (IVF) cycles.Keywords: Deoxyribonucleic acid fragmentation, male infertility, paternal age, semen quality, sperm coun

Stochastic Mean-Field Theory for the Disordered Bose-Hubbard Model

We investigate the effect of diagonal disorder on bosons in an optical lattice described by an Anderson-Hubbard model at zero temperature. It is known that within Gutzwiller mean-field theory spatially resolved calculations suffer particularly from finite system sizes in the disordered case, while arithmetic averaging of the order parameter cannot describe the Bose glass phase for finite hopping $J>0$. Here we present and apply a new \emph{stochastic} mean-field theory which captures localization due to disorder, includes non-trivial dimensional effects beyond the mean-field scaling level and is applicable in the thermodynamic limit. In contrast to fermionic systems, we find the existence of a critical hopping strength, above which the system remains superfluid for arbitrarily strong disorder.Comment: 6 pages, 6 figure

Quantum analogue of the Kolmogorov-Arnold-Moser transition in the field induced barrier penetration in a quartic potential

Quantum signatures of the Kolmogorov-Arnold-Moser (KAM) transition from the regular to chaotic classical dynamics of a double-well oscillator in the presence of an external monochromatic field of different amplitudes are analysed in terms of the corresponding Bohmian trajectories. It is observed that the classical chaos generally enhances the quantum fluctuations, while the quantum nonclassical effects try to suppress classical stochasticity

Journey Sustainability Analysis Report

This report contains an analysis of the transport emissions and occupancy for the transport network within Manchester. The study aims to identify the differences in travel distance, travel time and CO2 emissions per occupant for different journeys in Manchester using methods in emissions estimation described in the report 12.6.2 Occupancy/Emissions Sustainability Metric Matrix

Occupancy / Emissions Sustainability Metric Matrix

This report investigates occupancy/emission metrics for public and private domestic urban transportation and develops an emissions/sustainability matrix for the future development of a 'Green Travel Planning Tool'. The objective of this research is to 1) Review the current methods of estimating occupancy/emissions for various modes of transportation and to update these for accuracy; 2) Produce a sustainability/emissions matrix; 3) Compare the metrics developed with results from existing door-to-door journey planners producing their own estimates. Existing journey planners providing emission estimates typically use distance, estimated travel time and different modes of transportation as factors. The matrix produced here incorporates multiple additional factors (E.g. travel speed, embodied energy use based on fuel type) in an attempt to accurately estimate emissions per journey. The study includes the following:- 1. Identification of the latest average emissions for each mode of urban transport (normalised by occupancy) 2. A List of emissions occupancy estimation proxies and conversion factors where applicable 3. Identification of measurements and variables required for emissions and occupancy estimates. 4. Study of how existing journey planners produce their emissions results using different metrics. 5. A dynamic matrix that can be used to compute emissions results for new journey planners