Lateral diffusion of receptor-ligand bonds in membrane adhesion zones: Effect of thermal membrane roughness

The adhesion of cells is mediated by membrane receptors that bind to complementary ligands in apposing cell membranes. It is generally assumed that the lateral diffusion of mobile receptor-ligand bonds in membrane-membrane adhesion zones is slower than the diffusion of unbound receptors and ligands. We find that this slowing down is not only caused by the larger size of the bound receptor-ligand complexes, but also by thermal fluctuations of the membrane shape. We model two adhering membranes as elastic sheets pinned together by receptor-ligand bonds and study the diffusion of the bonds using Monte Carlo simulations. In our model, the fluctuations reduce the bond diffusion constant in planar membranes by a factor close to 2 in the biologically relevant regime of small bond concentrations.Comment: 6 pages, 5 figures; to appear in Europhysics Letter

Quantifying the Spiritual: Incorporating Subjective Spirituality in Biomedical Research

Biomedical objectivity is a dominant health paradigm in the United States today. This paradigm views the body mostly as an object to be studied by objective means. These objective means are taken for granted as universal categories for comprehending truth in biomedicine. Lack of theoretical reflection leaves vital subjective attributes of experience out of the picture of health and healing, including lived subjective spiritual experience. This partly stems from definitions of spirituality that are lacking in explicating many elements of lived spiritual experience. Flawed definitions of spirituality are the result of both unchecked biomedical authoritative theoretical assumptions, and a lack of familiarity with scholarship in the social sciences and humanities

Impact of MyChart Communication on Provider Burden

Patient portals have shown promise in engaging individuals in the management of their health by allowing exchange of secure electronic messages with their providers. Increased messaging increases physician workload and contributes to burnout among primary care physicians. This project examines both patient and provider perspectives of MyChart messaging and suggests ways in which this tool can be better utilized.https://scholarworks.uvm.edu/fmclerk/1799/thumbnail.jp

The exceptional Herbig Ae star HD101412: The first detection of resolved magnetically split lines and the presence of chemical spots in a Herbig star

We obtained high-resolution, high signal-to-noise UVES and a few lower quality HARPS spectra revealing the presence of resolved magnetically split lines. HD101412 is the first Herbig Ae star for which the rotational Doppler effect was found to be small in comparison to the magnetic splitting. The measured mean magnetic field modulus varies from 2.5 to 3.5kG, while the mean quadratic field was found to vary in the range of 3.5 to 4.8kG. To determine the period of variations, we used radial velocity, equivalent width, line width, and line asymmetry measurements of variable spectral lines of several elements, as well as magnetic field measurements. The most pronounced variability was detected for spectral lines of He I and the iron peak elements, whereas the spectral lines of CNO elements are only slightly variable. From spectral variations and magnetic field measurements we derived a potential rotation period P_rot=13.86d, which has to be proven in future studies with a larger number of observations. It is the first time that the presence of element spots is detected on the surface of a Herbig Ae/Be star. Our previous study of Herbig Ae stars revealed a trend towards stronger magnetic fields for younger Herbig Ae stars, confirmed by statistical tests. This is in contrast to a few other (non-statistical) studies claiming that magnetic Herbig Ae stars are progenitors of the magnetic Ap stars. New developments in MHD theory show that the measured magnetic field strengths are compatible with a current-driven instability of toroidal fields generated by differential rotation in the stellar interior. This explanation for magnetic intermediate-mass stars could be an alternative to a frozen-in fossil field.Comment: 7 pages, 6 figures, 1 table, to appear in Astronomische Nachrichte

Some Observations on the Handling of Adams\u27 Platinum-Oxide Hydrogenation Catalyst

Two problems are present in the measurement of the exact quantities of catalyst used in hydrogenations with platinum oxide. The first arises from the fact that platinum oxide is highly adsorbent and rapidly gains weight due to adsorption of atmospheric components when it is exposed to air. A procedure is described for making an approximate correction for this weight gain. The second problem is the identity of the actual catalytic material. The observations indicate that this is platinum metal, and it is shown that the platinum content varies with the batch of catalyst

Wigner crystals in two-dimensional transition-metal dichalcogenides: Spin physics and readout

Wigner crystals are prime candidates for the realization of regular electron lattices under minimal requirements on external control and electronics. However, several technical challenges have prevented their detailed experimental investigation and applications to date. We propose an implementation of two-dimensional electron lattices for quantum simulation of Ising spin systems based on self-assembled Wigner crystals in transition-metal dichalcogenides. We show that these semiconductors allow for minimally invasive all-optical detection schemes of charge ordering and total spin. For incident light with optimally chosen beam parameters and polarization, we predict a strong dependence of the transmitted and reflected signals on the underlying lattice periodicity, thus revealing the charge order inherent in Wigner crystals. At the same time, the selection rules in transition-metal dichalcogenides provide direct access to the spin degree of freedom via Faraday rotation measurements.Comment: 15 pages, 12 figure

Procalcitonin: Importance for the diagnosis of bacterial infections

In contrast to calcitonin which is primarily synthesized in the thyroid, procalcitonin is a prohormone which is synthesized in many different tissues of infected organs. To diagnose mild, localized, or early infections an assay needs to have a functional assay sensivity of approximately 0.02μg/L. We demonstrated that procalcitonin modifies the outcome of respiratory infections with regard to minimizing the use of antibiotics and duration of antibiotic treatment. High concentrations, especially over time, indicate high risk of a severe outcome. In this respect, procalcitonin is superior to other infection markers, such as C-reactive protein. High procalcitonin levels can also be found in non-bacterial diseases, such as malaria, severe trauma, burns, and medullar carcinoma of the thyroid. Procalcitonin, as a marker, has improved the diagnosis of bacterial infections. However, procalcitonin needs to be used in conjunction with other laboratory markers, clinical examination, and medical histor

Procalcitonin und seine Bedeutung für die Diagnose bakterieller Infektionen

Procalcitonin ist das Pro-Hormon von Calcitonin. Im Gegensatz zu Calcitonin, welches primär in der Schilddrüse gebildet wird, wird Procalcitonin bei einer bakteriellen Infektion im Körper von allen infizierten parenchymatösen Organen produzier

Connections to Self, Others and Higher Power in Relation to Self-Injury

Despite the growing attention to self-injury in non-clinical populations, college-age individuals have been underrepresented in the research. This study examined the role of connections to self, connections to others, and connections to higher power on propensity toward self-injury in a college population, from relational cultural and psychodynamic perspectives. Connection to self was measured by looking at alexithymia and attitude toward dreams; connection to others was measured by degree of interpersonal problems; and connection to higher power was measured by looking at spiritual transcendence. Alexithymia, interpersonal problems and positive attitude toward dreams were found to predict greater propensity toward self-injury, whereas spiritual connection was not. Students with alexithymia were found to have difficulties in interpersonal relationships and have more negative attitudes toward dreams

Diffusion algebras

We define the notion of "diffusion algebras". They are quadratic Poincare-Birkhoff-Witt (PBW) algebras which are useful in order to find exact expressions for the probability distributions of stationary states appearing in one-dimensional stochastic processes with exclusion. One considers processes in which one has N species, the number of particles of each species being conserved. All diffusion algebras are obtained. The known examples already used in applications are special cases in our classification. To help the reader interested in physical problems, the cases N=3 and 4 are listed separately.Comment: 29 pages; minor misprints corrected, few references adde