Expression of Complement and Toll-Like Receptor Pathway Genes is Associated with Malaria Severity in Mali: A Pilot Case Control Study

Background: The host response to infection by Plasmodium falciparum, the parasite most often responsible for severe malaria, ranges from asymptomatic parasitaemia to death. The clinical trajectory of malaria is influenced by host genetics and parasite load, but the factors determining why some infections produce uncomplicated malaria and some proceed to severe disease remain incompletely understood. Methods: To identify molecular markers of severe falciparum malaria, human gene expression patterns were compared between children aged 6 months to 5 years with severe and uncomplicated malaria who were enrolled in a case–control study in Bandiagara, Mali. Microarrays were used to obtain expression data on severe cases and uncomplicated controls at the time of acute disease presentation (five uncomplicated and five severe), 1 week after presentation (three uncomplicated and three severe) and treatment initiation, and in the subsequent dry season (late convalescence, four uncomplicated and four severe). This is a pilot study for the first use of microarray technology in Mali

Overtwisted energy-minimizing curl eigenfields

We consider energy-minimizing divergence-free eigenfields of the curl operator in dimension three from the perspective of contact topology. We give a negative answer to a question of Etnyre and the first author by constructing curl eigenfields which minimize $L^2$ energy on their co-adjoint orbit, yet are orthogonal to an overtwisted contact structure. We conjecture that $K$-contact structures on $S^1$-bundles always define tight minimizers, and prove a partial result in this direction.Comment: published versio

Concurrent application of tretinoin (retinoic acid) partially protects against corticosteroid-induced epidermal atrophy

Cutaneous atrophy arising from prolonged use of potent topical corticosteroids has long been a concern. Thus, it would be advantageous to find an agent which protects against atrophy produced by corticosteroids but at the same time does not impair their anti-inflammatory effects. Recent work shows that topical all- trans retinoic acid (tretinoin) prevents skin atrophy in mice treated with topical corticosteroids, but such studies have not been performed in humans. We performed an 8-week clinical, histological and biochemical study to test the ability of tretinoin to enhance efficacy and inhibit atrophogenicity of topical corticosteroids, when used in the treatment of psoriasis. In each of 20 psoriasis patients, one plaque, and its perilesional skin, was treated once daily with betamethasone dipropionate and tretinoin 0 1 , and one plaque, and its perilesional skin, treated with once daily betamethasone dipropionate and tretinoin vehicle. There was no difference in the speed or degree of improvement in plaques treated with either the topical corticosteroid tretinoin combination or with corticosteroid alone. Light microscopy revealed a 19 reduction in epidermal thickness, in corticosteroid-treated perilesional skin, as compared with a slight (1 ) increase in corticosteroid tretinoin-treated perilesional areas (P 0.067). Western blot analysis showed a 55 reduction in procollagen I aminopropeptide in perilesional skin treated with corticosteroid alone, as compared with a 45 reduction in corticosteroid tretinoin-treated perilesional skin. These data indicate that the addition of tretinoin does not impair the efficacy of a topical corticosteroid, in the treatment of psoriasis, and partially ameliorates epidermal atrophy produced by the topical corticosteroid.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75727/1/j.1365-2133.1996.d01-933.x.pd

Experimental observation of magnetic bobbers for a new concept of magnetic solid-state memory

The use of chiral skyrmions, which are nanoscale vortex-like spin textures, as movable data bit carriers forms the basis of a recently proposed concept for magnetic solid-state memory. In this concept, skyrmions are considered to be unique localized spin textures, which are used to encode data through the quantization of different distances between identical skyrmions on a guiding nanostripe. However, the conservation of distances between highly mobile and interacting skyrmions is difficult to implement in practice. Here, we report the direct observation of another type of theoretically-predicted localized magnetic state, which is referred to as a chiral bobber (ChB), using quantitative off-axis electron holography. We show that ChBs can coexist together with skyrmions. Our results suggest a novel approach for data encoding, whereby a stream of binary data representing a sequence of ones and zeros can be encoded via a sequence of skyrmions and bobbers. The need to maintain defined distances between data bit carriers is then not required. The proposed concept of data encoding promises to expedite the realization of a new generation of magnetic solid-state memory

Towards Physical Hybrid Systems

Some hybrid systems models are unsafe for mathematically correct but physically unrealistic reasons. For example, mathematical models can classify a system as being unsafe on a set that is too small to have physical importance. In particular, differences in measure zero sets in models of cyber-physical systems (CPS) have significant mathematical impact on the mathematical safety of these models even though differences on measure zero sets have no tangible physical effect in a real system. We develop the concept of "physical hybrid systems" (PHS) to help reunite mathematical models with physical reality. We modify a hybrid systems logic (differential temporal dynamic logic) by adding a first-class operator to elide distinctions on measure zero sets of time within CPS models. This approach facilitates modeling since it admits the verification of a wider class of models, including some physically realistic models that would otherwise be classified as mathematically unsafe. We also develop a proof calculus to help with the verification of PHS.Comment: CADE 201

Structural, chemical and magnetic properties of secondary phases in Co-doped ZnO

We have utilized a comprehensive set of experimental techniques such as transmission electron microscopy (TEM) and synchrotron-based x-ray absorption spectroscopy (XAS) and the respective x-ray linear dichroism and x-ray magnetic circular dichroism to characterize the correlation of structural, chemical and magnetic properties of Co-doped ZnO samples. It can be established on a quantitative basis that the superparamagnetic (SPM) behavior observed by integral superconducting quantum interference device magnetometry is not an intrinsic property of the material but stems from precipitations of metallic Co. Their presence is revealed by TEM as well as XAS. Annealing procedures for these SPM samples were also studied, and the observed changes in the magnetic properties found to be due to a chemical reduction or oxidation of the metallic Co species

Dynamic study of carbon nanotube growth and catalyst morphology evolution during acetylene decomposition on Co/SBA-15 in an environmental TEM

International @ SURFACES+FCA:MAO:ATUInternational audienceNon

Planet Hunters. V. A Confirmed Jupiter-Size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data

We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R_PL = 10.12 \pm 0.56 R_E) planet orbiting in the habitable zone of a solar-type star. PH2 b was elevated from candidate status when a series of false positive tests yielded a 99.9% confidence level that transit events detected around the star KIC 12735740 had a planetary origin. Planet Hunter volunteers have also discovered 42 new planet candidates in the Kepler public archive data, of which 33 have at least three transits recorded. Most of these transit candidates have orbital periods longer than 100 days and 20 are potentially located in the habitable zones of their host stars. Nine candidates were detected with only two transit events and the prospective periods are longer than 400 days. The photometric models suggest that these objects have radii that range between Neptune to Jupiter. These detections nearly double the number of gas giant planet candidates orbiting at habitable zone distances. We conducted spectroscopic observations for nine of the brighter targets to improve the stellar parameters and we obtained adaptive optics imaging for four of the stars to search for blended background or foreground stars that could confuse our photometric modeling. We present an iterative analysis method to derive the stellar and planet properties and uncertainties by combining the available spectroscopic parameters, stellar evolution models, and transiting light curve parameters, weighted by the measurement errors. Planet Hunters is a citizen science project that crowd-sources the assessment of NASA Kepler light curves. The discovery of these 43 planet candidates demonstrates the success of citizen scientists at identifying planet candidates, even in longer period orbits with only two or three transit events.Comment: 35 pages, 11 figures, 6 tables, accepted and published on ApJ ApJ, 776, 1

Mineral magnetism of dusty olivine:A credible recorder of pre-accretionary remanence

The magnetic properties of olivine-hosted Fe-Ni particles have been studied to assess the potential of “dusty olivine” to retain a pre-accretionary remanence in chondritic meteorites. Both body-centered (bcc) and face-centered cubic (fcc) Fe-Ni phases were formed by reduction of a terrestrial olivine precursor. The presence of Ni complicates the magnetic properties during heating and cooling due to the fcc-bcc martensitic transition. First-order reversal curve (FORC) diagrams contain a central ridge with a broad coercivity distribution extending to 600 mT, attributed to non-interacting single-domain (SD) particles, and a “butterfly” structure extending to 250 mT, attributed to single-vortex (SV) states. SD and SV states were imaged directly using electron holography. The location of the SD/SV boundary is broadly consistent with theoretical predictions. A method to measure the volume of individual SD particles using electron holography is presented. Combining the volume information with constraints on coercivity, we calculate the thermal relaxation characteristics of the particles and demonstrate that the high-coercivity component of remanance would remain stable for 4.6 Ga, even at temperatures approaching the Curie temperature of pure Fe. The high coercivity of the particles, together with the chemical protection offered by the surrounding olivine, is likely to make them resistant to shock remagnetization, isothermal remagnetization and terrestrial weathering, making dusty olivine a credible recorder of pre-accretionary magnetic fields