558 research outputs found
Magnetoelectric Effect and Spontaneous Polarization in HoFe(BO) and HoNdFe(BO)
The thermodynamic, magnetic, dielectric, and magnetoelectric properties of
HoFe(BO) and HoNdFe(BO) are
investigated. Both compounds show a second order Ne\'{e}l transition above 30 K
and a first order spin reorientation transition below 10 K.
HoFe(BO) develops a spontaneous electrical polarization below the
Ne\'{e}l temperature (T) which is diminished in external magnetic fields.
No magnetoelectric effect could be observed in HoFe(BO). In
contrast, the solid solution HoNdFe(BO) exhibits
both, a spontaneous polarization below T and a magnetoelectric effect at
higher fields that extends to high temperatures. The superposition of
spontaneous polarization, induced by the internal magnetic field in the ordered
state, and the magnetoelectric polarizations due to the external field results
in a complex behavior of the total polarization measured as a function of
temperature and field.Comment: 12 pages, 15 figure
Optical Flow Estimation in the Deep Learning Age
Akin to many subareas of computer vision, the recent advances in deep
learning have also significantly influenced the literature on optical flow.
Previously, the literature had been dominated by classical energy-based models,
which formulate optical flow estimation as an energy minimization problem.
However, as the practical benefits of Convolutional Neural Networks (CNNs) over
conventional methods have become apparent in numerous areas of computer vision
and beyond, they have also seen increased adoption in the context of motion
estimation to the point where the current state of the art in terms of accuracy
is set by CNN approaches. We first review this transition as well as the
developments from early work to the current state of CNNs for optical flow
estimation. Alongside, we discuss some of their technical details and compare
them to recapitulate which technical contribution led to the most significant
accuracy improvements. Then we provide an overview of the various optical flow
approaches introduced in the deep learning age, including those based on
alternative learning paradigms (e.g., unsupervised and semi-supervised methods)
as well as the extension to the multi-frame case, which is able to yield
further accuracy improvements.Comment: To appear as a book chapter in Modelling Human Motion, N. Noceti, A.
Sciutti and F. Rea, Eds., Springer, 202
Birthing practices of traditional birth attendants in South Asia in the context of training programmes
Traditional Birth Attendants (TBA) training has been an important component of public health policy interventions to improve maternal and child health in developing countries since the 1970s. More recently, since the 1990s, the TBA training strategy has been increasingly seen as irrelevant, ineffective or, on the whole, a failure due to evidence that the maternal mortality rate (MMR) in developing countries had not reduced. Although, worldwide data show that, by choice or out of necessity, 47 percent of births in the developing world are assisted by TBAs and/or family members, funding for TBA training has been reduced and moved to providing skilled birth attendants for all births. Any shift in policy needs to be supported by appropriate evidence on TBA roles in providing maternal and infant health care service and effectiveness of the training programmes. This article reviews literature on the characteristics and role of TBAs in South Asia with an emphasis on India. The aim was to assess the contribution of TBAs in providing maternal and infant health care service at different stages of pregnancy and after-delivery and birthing practices adopted in home births. The review of role revealed that apart from TBAs, there are various other people in the community also involved in making decisions about the welfare and health of the birthing mother and new born baby. However, TBAs have changing, localised but nonetheless significant roles in delivery, postnatal and infant care in India. Certain traditional birthing practices such as bathing babies immediately after birth, not weighing babies after birth and not feeding with colostrum are adopted in home births as well as health institutions in India. There is therefore a thin precarious balance between the application of biomedical and traditional knowledge. Customary rituals and perceptions essentially affect practices in home and institutional births and hence training of TBAs need to be implemented in conjunction with community awareness programmes
Casimir Force on Real Materials - the Slab and Cavity Geometry
We analyse the potential of the geometry of a slab in a planar cavity for the
purpose of Casimir force experiments. The force and its dependence on
temperature, material properties and finite slab thickness are investigated
both analytically and numerically for slab and walls made of aluminium and
teflon FEP respectively. We conclude that such a setup is ideal for
measurements of the temperature dependence of the Casimir force. By numerical
calculation it is shown that temperature effects are dramatically larger for
dielectrics, suggesting that a dielectric such as teflon FEP whose properties
vary little within a moderate temperature range, should be considered for
experimental purposes. We finally discuss the subtle but fundamental matter of
the various Green's two-point function approaches present in the literature and
show how they are different formulations describing the same phenomenon.Comment: 24 pages, 11 figures; expanded discussion, one appendix added, 1 new
figure and 10 new references. To appear in J. Phys. A: Math. Theo
The Chicken Yolk Sac IgY Receptor, a Mammalian Mannose Receptor Family Member, Transcytoses IgY across Polarized Epithelial Cells
In mammals the transfer of passive immunity from mother to young is mediated by the MHC-related receptor FcRn, which transports maternal IgG across epithelial cell barriers. In birds, maternal IgY in egg yolk is transferred across the yolk sac to passively immunize chicks during gestation and early independent life. The chicken yolk sac IgY receptor (FcRY) is the ortholog of the mammalian phospholipase A2 receptor, a mannose receptor family member, rather than an FcRn or MHC homolog. FcRn and FcRY both exhibit ligand binding at the acidic pH of endosomes and ligand release at the slightly basic pH of blood. Here we show that FcRY expressed in polarized mammalian epithelial cells functioned in endocytosis, bidirectional transcytosis, and recycling of chicken FcY/IgY. Confocal immunofluorescence studies demonstrated that IgY binding and endocytosis occurred at acidic but not basic pH, mimicking pH-dependent uptake of IgG by FcRn. Colocalization studies showed FcRY-mediated internalization via clathrin-coated pits and transport involving early and recycling endosomes. Disruption of microtubules partially inhibited apical-to-basolateral and basolateral-to-apical transcytosis, but not recycling, suggesting the use of different trafficking machinery. Our results represent the first cell biological evidence of functional equivalence between FcRY and FcRn and provide an intriguing example of how evolution can give rise to systems in which similar biological requirements in different species are satisfied utilizing distinct protein folds
Nail lacquer films’ surface energies and in vitro water-resistance and adhesion do not predict their in vivo residence
The in vivo residence of nail lacquers (which are ideal topical drug carriers for the treatment of nail diseases) determines their frequency of application, and is thereby expected to influence patient adherence and success of treatment. Thus in vitro measurements to indicate lacquers’ in vivo residence are routinely conducted during formulation development. However the literature on in vitro-in vivo correlations is severely limited. Thus, the aim of the work discussed in this paper was to investigate correlations between in vivo residence and in vitro film resistance to water, in vitro film adhesion and surface energy of lacquer films. In vivo measurements were conducted on fingernails in six volunteers. Seven commercially available nail lacquers were tested in commonly-used measurements. Correlations between in vivo residence and in vitro water resistance and adhesion were found to be extremely poor. The surface energies of the lacquer films (which were between 33 and 39 mJ/m2) were also not predictive of in vivo residence. High density polyethylene (HDPE) sheet – whose surface energy was determined to be similar to that of the human nailplate – was found to be a suitable model for the nailplate (when investigating surface energy) and was used in a number of experiments
RASSF1A–LATS1 signalling stabilizes replication forks by restricting CDK2-mediated phosphorylation of BRCA2
Genomic instability is a key hallmark of cancer leading to tumour heterogeneity and therapeutic resistance. BRCA2 has a fundamental role in error-free DNA repair but also sustains genome integrity by promoting RAD51 nucleofilament formation at stalled replication forks. CDK2 phosphorylates BRCA2 (pS3291-BRCA2) to limit stabilizing contacts with polymerized RAD51; however, how replication stress modulates CDK2 activity and whether loss of pS3291-BRCA2 regulation results in genomic instability of tumours are not known. Here we demonstrate that the Hippo pathway kinase LATS1 interacts with CDK2 in response to genotoxic stress to constrain pS3291-BRCA2 and support RAD51 nucleofilaments, thereby maintaining genomic fidelity during replication stalling. We also show that LATS1 forms part of an ATR-mediated response to replication stress that requires the tumour suppressor RASSF1A. Importantly, perturbation of the ATR–RASSF1A–LATS1 signalling axis leads to genomic defects associated with loss of BRCA2 function and contributes to genomic instability and ‘BRCA-ness’ in lung cancers
Prostate tumor attenuation in the nu/nu murine model due to anti-sarcosine antibodies in folate-targeted liposomes
Herein, we describe the preparation of liposomes with folate-targeting properties for the encapsulation of anti-sarcosine antibodies (antisarAbs@LIP) and sarcosine (sar@LIP). The competitive inhibitory effects of exogenously added folic acid supported the role of folate targeting in liposome internalization. We examined the effects of repeated administration on mice PC-3 xenografts. Sar@LIP treatment significantly increased tumor volume and weight compared to controls treated with empty liposomes. Moreover, antisarAbs@LIP administration exhibited a mild antitumor effect. We also identified differences in gene expression patterns post-treatment. Furthermore, Sar@LIP treatment resulted in decreased amounts of tumor zinc ions and total metallothioneins. Examination of the spatial distribution across the tumor sections revealed a sarcosine-related decline of the MT1X isoform within the marginal regions but an elevation after antisarAbs@LIP administration. Our exploratory results demonstrate the importance of sarcosine as an oncometabolite in PCa. Moreover, we have shown that sarcosine can be a potential target for anticancer strategies in management of PCa
Nanofluid impingement jet heat transfer
Experimental investigation to study the heat transfer between a vertical round alumina-water nanofluid jet and a horizontal circular round surface is carried out. Different jet flow rates, jet nozzle diameters, various circular disk diameters and three nanoparticles concentrations (0, 6.6 and 10%, respectively) are used. The experimental results indicate that using nanofluid as a heat transfer carrier can enhance the heat transfer process. For the same Reynolds number, the experimental data show an increase in the Nusselt numbers as the nanoparticle concentration increases. Size of heating disk diameters shows reverse effect on heat transfer. It is also found that presenting the data in terms of Reynolds number at impingement jet diameter can take into account on both effects of jet heights and nozzle diameter. Presenting the data in terms of Peclet numbers, at fixed impingement nozzle diameter, makes the data less sensitive to the percentage change of the nanoparticle concentrations. Finally, general heat transfer correlation is obtained verses Peclet numbers using nanoparticle concentrations and the nozzle diameter ratio as parameters
Drivers of Performance
This chapter uses the annual school census to analyze differences in primary school performances across regions. Our results, obtained from a stochastic frontier analysis, suggest that differences in efficiency explain only part of the observed variation, while resource availability is the most important driver of performance differences. In addition to this, we note that resources are distributed quite unevenly among regions and schools. By distributing more school inputs, or distributing existing inputs more equally to the benefit of underserved schools, performance can be expected to go up
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