Flux through a hole from a shaken granular medium

We have measured the flux of grains from a hole in the bottom of a shaken container of grains. We find that the peak velocity of the vibration, vmax, controls the flux, i.e., the flux is nearly independent of the frequency and acceleration amplitude for a given value of vmax. The flux decreases with increasing peak velocity and then becomes almost constant for the largest values of vmax. The data at low peak velocity can be quantitatively described by a simple model, but the crossover to nearly constant flux at larger peak velocity suggests a regime in which the granular density near the container bottom is independent of the energy input to the system.Comment: 14 pages, 4 figures. to appear in Physical Review

Experimental and ab initio determination of the bending potential of HCP

The emission properties of HCP excited to the A, B, and d electronic states have been studied. Lifetimes and quenching rates have been measured. By spectrally resolving the emission spectrum, the energy of 94 vibrational levels of the ground electronic state have been measured to an accuracy of ≈5 cm−1. These energy levels were fit to experimental accuracy by a rigid bender Hamiltonian thereby determining the bending potential over a range of bending angle from 0 to 100° (0–17 500 cm−1). An ab initio bending potential has been computed for HCP and found to be in excellent agreement with the experimentally fitted one over the range that the experimental data span. This potential predicts that HPC has an energy maximum with respect to the bending coordinate. The bending potential decreases monotonically by about 30 000 cm−1 in going from HPC to HCP.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69992/2/JCPSA6-82-10-4460-1.pd

Medical abortion with mifepristone and vaginal misoprostol between 64 and 70 days' gestation.

ObjectiveTo evaluate outcomes with mifepristone 200 mg orally followed 24-48 h later by misoprostol 800 mcg vaginally for medical abortion at 64-70 days of gestation.Study designWe reviewed electronic databases and medical records for medical abortion cases at 64-70 days' gestation at British Pregnancy Advisory Service clinics in England and Wales from May 2015 through October 2016. Women selected in-office follow-up or self-evaluation of abortion outcome using a checklist along with low-sensitivity urine pregnancy testing. We excluded cases in which we could not locate records and when women did not proceed with medical abortion, did not use misoprostol following mifepristone if abortion had not occurred and did not attend a scheduled follow-up assessment. We analyzed demographic characteristics, treatment outcomes and significant adverse events. We defined treatment success as complete abortion without surgical evacuation and without continuing pregnancy.ResultsOf 2743 cases identified, we could not locate 40 charts and excluded 30 cases, leaving a final sample of 2673. Overall, 2538 (94.9%, 95% CI 94.1-95.8) women had a successful medical abortion. Reasons for failure included continuing pregnancy (n=90, 3.4%, 95% CI 2.7-4.1), retained nonviable pregnancy (n=2, 0.1%, 95% CI 0-0.2) and incomplete abortion (n=43, 1.6%, 95% CI 1.1-2.1). Of those with continuing pregnancies, 81 underwent a uterine aspiration and 9 opted to continue the pregnancy. Thirty-five (1.3%, 95% CI 0.9-1.7) women had significant adverse events; 16 (0.6%, 95% CI 0.3-0.9) underwent an in-hospital aspiration. Pelvic infection (n=4, 0.2%) and transfusion (n=1, 0.03%) occurred rarely.ConclusionMedical abortion from 64 to 70 days with mifepristone and vaginal misoprostol is effective with a low rate of serious adverse events.ImplicationsMedical abortion between 64 and 70 days of gestation may be offered on an outpatient basis using mifepristone and vaginal misoprostol. Service provision without an in-person follow-up is feasible. Not all women with a continuing pregnancy after medical abortion treatment opt to have an aspiration procedure

Sequential development of interleukin 2–dependent effector and regulatory T cells in response to endogenous systemic antigen

Transfer of naive antigen-specific CD4+ T cells into lymphopenic mice that express an endogenous antigen as a systemic, secreted protein results in severe autoimmunity resembling graft-versus-host disease. T cells that respond to this endogenous antigen develop into effector cells that cause the disease. Recovery from this disease is associated with the subsequent generation of FoxP3+CD25+ regulatory cells in the periphery. Both pathogenic effector cells and protective regulatory cells develop from the same antigen-specific T cell population after activation, and their generation may occur in parallel or sequentially. Interleukin (IL)-2 plays a dual role in this systemic T cell reaction. In the absence of IL-2, the acute disease is mild because of reduced T cell effector function, but a chronic and progressive disease develops late and is associated with a failure to generate FoxP3+ regulatory T (T reg) cells in the periphery. Thus, a peripheral T cell reaction to a systemic antigen goes through a phase of effector cell–mediated pathology followed by T reg cell–mediated recovery, and both require the growth factor IL-2

Rapid colour changes in Euglena sanguinea (Euglenophyceae) caused by internal lipid globule migration

The accumulation of red pigments under chronic stress is a response observed in most groups of oxygenic photoautotrophs. It is thought that the red pigments in the cell shield the chlorophyll located underneath from the light. Among these red pigments, the accumulation of carotenoids is one of the most frequent cases. However, the synthesis or degradation of carotenoids is a slow process and this response is usually only observed when the stress is maintained over a period of time. In the Euglenophyte Euglena sanguinea, this is due to the accumulation of a large amount of free and esterified astaxanthin (representing 80% of the carotenoid pool). While reddening is a slow and sometimes irreversible process in other phototrophs, reducing the efficiency of light harvesting by chlorophyll, in E. sanguinea it is highly dynamic, capable of shifting from red to green (and vice-versa) in 10-20 min. This change is not due to de novo carotenogenesis, but to the relocation of cytoplasmic lipid globules where astaxanthin accumulates. Thus, red globules migrate from the centre of the cell to peripheral locations when photoprotection is demanded. This protective system seems to be so efficient that other classical mechanisms are not operative in this species. For example, despite the presence and operation of the diadino-diatoxanthin cycle, nonphotochemical quenching (NPQ) is almost undetectable. Since E. sanguinea forms extensive floating colonies, reddening can be observed at much greater scale than at a cellular level, the mechanism described here being one of the fastest and most dramatic colour changes attributable to photosynthetic organisms at cell and landscape level. In sum, these data indicate an extremely dynamic and efficient photoprotective mechanism based on organelle migration more than on carotenoid biosynthesis that prevents excess light absorption by chlorophylls reducing the need for other protective processes related to energy dissipation.This work was supported by the Basque Government [UPV/EHU-GV IT-1018-16] [UPV/EHU PPG17/67 – GV IT-1040-16], and by the Spanish Ministry of Economy and Competitiveness (MINECO) and the European Research and Development Foundation (FEDER) through (i) [CTM2014-53902-C2-2-P] national grant and (ii) a “Juan de la Cierva-Incorporación” postdoctoral grant [IJCI-2014-22489] to BFM

Role of IL-17 and regulatory T lymphocytes in a systemic autoimmune disease

To explore the interactions between regulatory T cells and pathogenic effector cytokines, we have developed a model of a T cell–mediated systemic autoimmune disorder resembling graft-versus-host disease. The cytokine responsible for tissue inflammation in this disorder is interleukin (IL)-17, whereas interferon (IFN)-γ produced by Th1 cells has a protective effect in this setting. Because of the interest in potential therapeutic approaches utilizing transfer of regulatory T cells and inhibition of the IL-2 pathway, we have explored the roles of these in the systemic disease. We demonstrate that the production of IL-17 and tissue infiltration by IL-17–producing cells occur and are even enhanced in the absence of IL-2. Regulatory T cells favor IL-17 production but prevent the disease when administered early in the course by suppressing expansion of T cells. Thus, the pathogenic or protective effects of cytokines and the therapeutic capacity of regulatory T cells are crucially dependent on the timing and the nature of the disease

An algal enzyme required for biosynthesis of the most abundant marine carotenoids.

Fucoxanthin and its derivatives are the main light-harvesting pigments in the photosynthetic apparatus of many chromalveolate algae and represent the most abundant carotenoids in the world's oceans, thus being major facilitators of marine primary production. A central step in fucoxanthin biosynthesis that has been elusive so far is the conversion of violaxanthin to neoxanthin. Here, we show that in chromalveolates, this reaction is catalyzed by violaxanthin de-epoxidase-like (VDL) proteins and that VDL is also involved in the formation of other light-harvesting carotenoids such as peridinin or vaucheriaxanthin. VDL is closely related to the photoprotective enzyme violaxanthin de-epoxidase that operates in plants and most algae, revealing that in major phyla of marine algae, an ancient gene duplication triggered the evolution of carotenoid functions beyond photoprotection toward light harvesting

OWL-based acquisition and editing of computer-interpretable guidelines with the CompGuide editor

Computer-Interpretable Guidelines (CIGs) are the dominant medium for the delivery of clinical decision support, given the evidence-based nature of their source material. Therefore, these machine-readable versions have the ability to improve practitioner performance and conformance to standards, with availability at the point and time of care. The formalisation of Clinical Practice Guideline knowledge in a machine-readable format is a crucial task to make it suitable for the integration in Clinical Decision Support Systems. However, the current tools for this purpose reveal shortcomings with respect to their ease of use and the support offered during CIG acquisition and editing. In this work, we characterise the current landscape of CIG acquisition tools based on the properties of guideline visualisation, organisation, simplicity, automation, manipulation of knowledge elements, and guideline storage and dissemination. Additionally, we describe the CompGuide Editor, a tool for the acquisition of CIGs in the CompGuide model for Clinical Practice Guidelines that also allows the editing of previously encoded guidelines. The Editor guides the users throughout the process of guideline encoding and does not require proficiency in any programming language. The features of the CIG encoding process are revealed through a comparison with already established tools for CIG acquisition.COMPETE, Grant/Award Number: POCI-01-0145-FEDER-007043; FCT - Fundacao para a Ciencia e Tecnologia, Grant/Award Number: UID/CEC/00319/201

A global formalism incorporating constants of motion and other constraints in the classical description of chemical rate processes

A phase space cell method for providing a global description of the motions of a physical system is outlined. The key feature is a coarse-graining approximation to the phase-space probability distribution. Constants of motion and other constraints are incorporated to reduce the dimensionality of computations. Time-independent and time-dependent methods of solution are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23339/1/0000279.pd