Kinetic energy functional for Fermi vapors in spherical harmonic confinement

Two equations are constructed which reflect, for fermions moving independently in a spherical harmonic potential, a differential virial theorem and a relation between the turning points of kinetic energy and particle densities. These equations are used to derive a differential equation for the particle density and a non-local kinetic energy functional.Comment: 8 pages, 2 figure

Metastable states of a ferromagnet on random thin graphs

We calculate the mean number of metastable states of an Ising ferromagnet on random thin graphs of fixed connectivity c. We find, as for mean field spin glasses that this mean increases exponentially with the number of sites, and is the same as that calculated for the +/- J spin glass on the same graphs. An annealed calculation of the number <N_{MS}(E)> of metastable states of energy E is carried out. For small c, an analytic result is obtained. The result is compared with the one obtained for spin glasses in order to discuss the role played by loops on thin graphs and hence the effect of real frustration on the distribution of metastable states.Comment: 15 pages, 3 figure

Multicolour detection of every chromosome as a means of detecting mosaicism and nuclear organisation in human embryonic nuclei

Fluorescence in situ Hybridisation (FISH) revolutionised cytogenetics using fluorescently labelled probes with high affinity with target (nuclear) DNA. By the early 1990s FISH was adopted as a means of PGD sexing for couples at risk of transmitting X-linked disorders and later for detection of unbalanced translocations. Following a rise in popularity of PGD by FISH for sexing and the availability of multicolour probes (5-8 colour), the use of FISH was expanded to the detection of aneuploidy and selective implantation of embryos more likely to be euploid, the rationale being to increase pregnancy rates (referral categories were typically advanced maternal age, repeated IVF failure, repeated miscarriage or severe male factor infertility). Despite initial reports of an increase in implantation rates, reduction in trisomic offspring and spontaneous abortions criticism centred around experimental design (including lack of randomisation), inadequate control groups and lack of report on live births. Eleven randomised control trials (RCTs) (2004-2010) showed that PGS with FISH did not increase delivery rates with some demonstrating adverse outcomes. These RCTs, parallel improvements in culturing and cryopreservation and a shift to blastocyst biopsy essentially outdated FISH as a tool for PGS and it has now been replaced by newer technologies (array CGH, SNP arrays, qRT-PCR and NGS). Cell-by-cell follow up analysis of individual blastomeres in non-transferred embryos is however usually prohibitively expensive by these new approaches and thus FISH remains an invaluable resource for the study of mosaicosm and nuclear organization. We thus developed the approach described herein for the FISH detection of chromosome copy number of all 24 human chromosomes. This approach involves 4 sequential layers of hybridization, each with 6 spectrally distinct fluorochromes and a bespoke capturing system. Here we report previously published studies and hitherto unreported data indicating that 24 chromosome FISH is a useful tool for studying chromosome mosaicism, one of the most hotly debated topics currently in preimplantation genetics. Our results suggest that mosaic embryo aneuploidy is not highly significantly correlated to maternal age, probably due, in part, to the large preponderance of post-zygotic (mitotic) errors. Chromosome loss (anaphase lag) appears to be the most common mechanism, followed by chromosome gain (endoreduplication), however 3:1 mitotic non- disjunction of chromosomes appears to be rare. Nuclear organisation (i.e. the spatial and temporal topology of chromosomes or sub-chromosomal compartments) studies indicate that human morula or blastocyst embryos (day 4-5) appear to adopt a "chromocentric" pattern (i.e. almost all centromeric signals reside in the innermost regions of the nuclear volume). By the blastocyst stage however, a more ordered organisation with spatial and temporal cues important for embryo development appears. We have however found no association between aneuploidy and nuclear organization using this approach despite our earlier studies. In conclusion, while FISH is mostly "dead and buried" for mainstream PGS, it still has a place for basic biology studies; the development of a 24 chromosome protocol extends the power of this analysis

Covariance matrices and the separability problem

We propose a unifying approach to the separability problem using covariance matrices of locally measurable observables. From a practical point of view, our approach leads to strong entanglement criteria that allow to detect the entanglement of many bound entangled states in higher dimensions and which are at the same time necessary and sufficient for two qubits. From a fundamental perspective, our approach leads to insights into the relations between several known entanglement criteria -- such as the computable cross norm and local uncertainty criteria -- as well as their limitations.Comment: 4 pages, no figures; v3: final version to appear in PR

Phase inversion phenomenon in horizontal dispersed oil/water pipeline flows

This thesis reports on experimental and theoretical investigations relevant to the understanding of the phenomenon of phase inversion and its effect on pressure drop during dispersed flow of two immiscible liquids in horizontal pipelines. Experimental studies of phase inversion and associated phenomena were carried out in the liquid flow facility in the Department of Chemical Engineering at University College London (UCL), and at the Norwegian University of Science and Technology, Trondheim, Norway (NTNU). Detailed local conductivity measurements have been obtained at UCL (using conductivity ring probes, a local needle conductivity probe and a flush probe mounted on the pipe wall), which revealed phase continuity at different locations in the pipe cross section as the system approaches phase inversion and after it. In both systems, pressure gradient was measured and phase inversion identification measurements along the pipe were enabled with the use of the conductivity ring probes. A new probe that enables phase and drop size distribution measurements was designed and developed for use at UCL. At the UCL facility, velocity ratio of the two phases, the dispersed phase droplet velocity profiles, and phase distribution at the pipe cross section and droplet chord length were also measured. This revealed a significant increase in the dispersed drop size at inversion point. The results also enabled the equal surface energy criterion validation, based on droplet size considerations. The velocity ratio of the two phases was found to have a higher value than unity at all conditions studied, while inversion from water to oil continuous mixtures results in a decrease in its value. The drop velocity was also becoming lower with increasing dispersed phase fraction and it was found to be affected by the presence of high dispersed phase concentrations. Various parameters and their effect on inversion were studied. Three types of oil (with viscosities of 1.7, 5.5 and 11 mPa s) were used while different pipe diameters and materials were tested (namely, acrylic with 32 and 60 mm ID, stainless steel with 38 and 60 mm ID and an epoxy coated stainless steel pipe with 60 mm ID). Mixture velocities from 2.5 m/s to 6.2 m/s (depending on the test section) were used, selected so that the mixture away from the inversion was dispersed. Also, two experimental routes were followed, starting from oil continuous and water continuous dispersions to investigate the existence of a possible hysteresis at the occurrence of inversion. It was found that phase inversion is accompanied with significant changes in pressure gradient it was preceded by a sharp peak when the less viscous oils were used, while no peak was recorded with the use of the more viscous oil. An ambivalent range was seen for the less viscous oil, possibly related to the creation of secondary dispersions. A mechanistic model that describes the layered structure of the flow during inversion (detected experimentally) was proposed for the prediction of flow characteristics and pressure gradient at the region of inversion. It is suggested that inversion starts when a thin layer of the dispersed phase (that is to become continuous) forms at the top or the bottom of the pipe. A clear layer of the continuous phase may also exist at the bottom or the top of the pipe respectively. Two or three layer models were used for these configurations. Results showed that the two layer model predicts pressure gradient and layer thickness well. The homogeneous model was found to agree well with the experimental results, especially in the water continuous region when considerations for the mixture velocity. The friction factor was modified to compensate for the appearance of the drag reduction in the conducted measurements. In addition, a commercial feasibility study has been carried out which confirmed the considerable and immediate potential for the commercialisation of the impedance probe developed within this research for phase and drop size distribution measurements

The combined molecular adjuvant CASAC enhances the CD8+ T cell response to a tumor-associated self-antigen in aged, immunosenescent mice

BACKGROUND: Ineffective induction of T cell mediated immunity in older individuals remains a persistent challenge for vaccine development. Thus, there is a need for more efficient and sophisticated adjuvants that will complement novel vaccine strategies for the elderly. To this end, we have investigated a previously optimized, combined molecular adjuvant, CASAC (Combined Adjuvant for Synergistic Activation of Cellular immunity), incorporating two complementary Toll-like receptor agonists, CpG and polyI:C, a class-II epitope, and interferon (IFN)-γ in aged mice. FINDINGS: In aged mice with typical features of immunosenescence, antigen specific CD8+ T cell responses were stimulated after serial vaccinations with CASAC or Complete/Incomplete Freund's Adjuvant (CFA/IFA) and a class I epitope, deriving either from ovalbumin (SIINFEKL, SIL) or the melanoma-associated self-antigen, tyrosinase-related protein-2 (SVYDFFVWL, SVL). Pentamer analysis revealed that aged, CASAC/SIL-vaccinated animals had substantially higher frequencies of H-2K(b)/SIL-specific CD8+ T cells compared to the CFA/IFA-vaccinated groups. Similarly, higher frequencies of H-2K(b)/SVL-pentamer+ and IFN-γ+ CD8+ T cells were detected in the aged, CASAC + SVL-vaccinated mice than in their CFA/IFA-vaccinated counterparts. In both antigen settings, CASAC promoted significantly better functional CD8+ T cell activity. CONCLUSION: These studies demonstrate that functional CD8+ T cells, specific for both foreign and tumour-associated self-antigens, can be effectively induced in aged immunosenescent mice using the novel multi-factorial adjuvant CASAC

Emission reduction via supply chain coordination

This paper examines the environmental impact of potential coordination on supply chains. A decentralized two-node supply chain is studied, in which one node is a buyer ordering from a second node, who is a supplier operating under the lot-for-lot policy. The supplier is allowed to use a quantity discount to manipulate the buyer's decision reducing both his individual cost and system's operational costs. This results in decreasing the frequency of deliveries. We demonstrate that environmentally friendly policies could be also cost saving. The crucial factor about the environmental benefits is the total distance travelled rather than the vehicle loads. We establish the magnitude of the environmental benefits using numerical examples under specific operational parameters. Complete and incomplete information cases are investigated, where the buyer and the supplier make their decisions to optimize their own business operations

Inventory of alien marine species of Cyprus (2009)

An updated inventory of alien marine species from coastal and offshore waters of Cyprus is presented. Records were compiled based on the existing scientific and grey literature, including HCMR database of Mediterranean alien species, technical reports, scientific congresses, academic dissertations, and websites, as well as on unpublished/personal observations. The listed species were classified in one of five categories: established, invasive, casual, cryptogenic, and questionable. The mode of introduction and the year of first sighting were also reported for each species. Eight new records based on personal observations of the authors were reported (Chondria coerulescens, Neosiphonia sphaerocarpa, Enchelycore anatina, Lagocephalus spadiceus, Lagocephalus suezensis, Scomberomorus commerson, Sillago sihama, and Sphoeroides pachygaster). Nine species, previously reported as aliens in Cypriot waters, were excluded from the inventory for various reasons. Ten established species were characterized as invasive (Caulerpa racemosa var. cylindracea, Cerithium scabridum, Strombus persicus, Trochus erythraeus, Brachidontes pharaonis, Pinctada radiata, Fistularia commersonii, Lagocephalus sceleratus, Siganus luridus, and Siganus rivulatus) as they have a substantial impact on biodiversity and/or local economy. The impact of alien marine species in Cyprus is expected to grow in the close future, and further effort directed towards recording alien invasions and their impact will be needed

An automatic image analysis methodology for the measurement of droplet size distributions in liquid–liquid dispersion: round object detection

This article presents an efficient and economical automatic image analysis technique for the droplet characterization in a liquid–liquid dispersion. The methodology employs a combination of the Satoshi Suzuki's [Topological structural analysis of digitized binary images by border following. Comput Vis Graph Image Process. 1985;30:32–46] find contours algorithm and the method of minimal enclosing circle identification, proposed by Emo Welzl [Smallest enclosing disks (balls and ellipsoids). Berlin, Heidelberg: Springer; 1991. p. 359–370. chapter 24], to achieve the objectives. The round object detection algorithm has been designed for the identification and verification of correct droplets in the mixture which helped to increase the accuracy of automatic detection. Tests have been performed on various sets of images obtained during several emulsification processes and contain examples of droplets which differ in size, density, volume and appearance etc. An effective communication between the two methodologies and newly introduced algorithms demonstrated an accuracy of 90% or above in the measurement of droplet size distribution and Sauter mean diameters through an automatic vision-based system