Integrability of a conducting elastic rod in a magnetic field

We consider the equilibrium equations for a conducting elastic rod placed in a uniform magnetic field, motivated by the problem of electrodynamic space tethers. When expressed in body coordinates the equations are found to sit in a hierarchy of non-canonical Hamiltonian systems involving an increasing number of vector fields. These systems, which include the classical Euler and Kirchhoff rods, are shown to be completely integrable in the case of a transversely isotropic rod; they are in fact generated by a Lax pair. For the magnetic rod this gives a physical interpretation to a previously proposed abstract nine-dimensional integrable system. We use the conserved quantities to reduce the equations to a four-dimensional canonical Hamiltonian system, allowing the geometry of the phase space to be investigated through Poincar\'e sections. In the special case where the force in the rod is aligned with the magnetic field the system turns out to be superintegrable, meaning that the phase space breaks down completely into periodic orbits, corresponding to straight twisted rods.Comment: 19 pages, 1 figur

High-throughput synchrotron X-ray diffraction for combinatorial phase mapping

Discovery of new materials drives the deployment of new technologies. Complex technological requirements demand precisely tailored material functionalities, and materials scientists are driven to search for these new materials in compositionally complex and often non-equilibrium spaces containing three, four or more elements. The phase behavior of these high-order composition spaces is mostly unknown and unexplored. High-throughput methods can offer strategies for efficiently searching complex and multi-dimensional material genomes for these much needed new materials and can also suggest a processing pathway for synthesizing them. However, high-throughput structural characterization is still relatively under-developed for rapid material discovery. Here, a synchrotron X-ray diffraction and fluorescence experiment for rapid measurement of both X-ray powder patterns and compositions for an array of samples in a material library is presented. The experiment is capable of measuring more than 5000 samples per day, as demonstrated by the acquisition of high-quality powder patterns in a bismuth-vanadium-iron oxide composition library. A detailed discussion of the scattering geometry and its ability to be tailored for different material systems is provided, with specific attention given to the characterization of fiber textured thin films. The described prototype facility is capable of meeting the structural characterization needs for the first generation of high-throughput material genomic searches

Combined Chlorophyll Fluorescence and Transcriptomic Analysis Identifies the P3/P4 Transition as a Key stage in Rice Leaf Photosynthetic Development

Leaves are derived from heterotrophic meristem tissue that, at some point, must make the transition to autotrophy via the initiation of photosynthesis. However, the timing and spatial coordination of the molecular and cellular processes underpinning this switch are poorly characterized. Here, we report on the identification of a specific stage in rice (Oryza sativa) leaf development (P3/P4 transition) when photosynthetic competence is first established. Using a combined physiological and molecular approach, we show that elements of stomatal and vascular differentiation are coordinated with the onset of measurable light absorption for photosynthesis. Moreover, by exploring the response of the system to environmental perturbation, we show that the earliest stages of rice leaf development have significant plasticity with respect to elements of cellular differentiation of relevance for mature leaf photosynthetic performance. Finally, by performing an RNA sequencing analysis targeted at the early stages of rice leaf development, we uncover a palette of genes whose expression likely underpins the acquisition of photosynthetic capability. Our results identify the P3/P4 transition as a highly dynamic stage in rice leaf development when several processes for the initiation of photosynthetic competence are coordinated. As well as identifying gene targets for future manipulation of rice leaf structure/function, our data highlight a developmental window during which such manipulations are likely to be most effective

Trajectories of long-term exposure to anticholinergic and sedative drugs: A latent class growth analysis

Introduction: A variety of drugs, which are frequently prescribed to older people, have anticholinergic and sedative effects whereby they may impair cognitive and physical function. Although substantial inter-individual variation in anticholinergic and sedative exposure has been documented, little is known about subpopulations with distinct trajectories of exposure. Methods: Data from the Longitudinal Aging Study Amsterdam (LASA), an ongoing Dutch population-based cohort study, collected over 20 years (1992-2012) at seven occasions, were analyzed. On each occasion, cumulative anticholinergic and sedative exposure was quantified with the Drug Burden Index, a linear additive pharmacological dose-response model. The most likely number of trajectories were empirically derived with Latent Class Growth Analysis using "Goodness of fit" statistics. Trajectories were then compared on physical and cognitive function. Results: A total of 763 participants completed all follow-ups (61% women; mean age 83, ±6). "Goodness of fit" statistics (Bayesian In-formation Criterion = 22916, Bootstrapped Likelihood Ratio Test of 3 vs. 2 classes = 514.12

Условия формирования зон скопления метана в углепородном массиве

Розглянуті основні геологічні чинники, які впливають на формування зон скупчення метану у вуглепородному масиві. Виділені, найбільш ефективні показники для середнього катагенеза порід – опосередковані локальні структури, зони тріщинуватості порід, стрижневі ділянки пісковиків (палеопотоки). Для виділених показників виконаний розрахунок дисперсійного аналізу по альтернативній ознаці. На основі розрахунків встановлено вплив кожного фактора на формування зон скупчення метану у вуглепродному масиві.Basic geological factors, which influence on forming of zone of accumulation of methane in coalrock massif, are presented. The most effective indexes for middle katagenesis of rock are determinated - medial local structures, zone of jointing of rock, race areas of sandstones (paleocurrent). For determinated indexes calculation of dispersion on an alternative character is executed. On the basis of calculations influence of every factor on forming of zone of accumulation of methane in a coalrock massif is definited

Folding factors and partners for the intrinsically disordered protein Micro-Exon Gene 14 (MEG-14)

The micro-exon genes (MEG) of Schistosoma mansoni, a parasite responsible for the second most widely spread tropical disease, code for small secreted proteins with sequences unique to the Schistosoma genera. Bioinformatics analyses suggest the soluble domain of the MEG-14 protein will be largely disordered, and using synchrotron radiation circular dichroism spectroscopy, its secondary structure was shown to be essentially completely unfolded in aqueous solution. It does, however, show a strong propensity to fold into more ordered structures under a wide range of conditions. Partial folding was produced by increasing temperature (in a reversible process), contrary to the behavior of most soluble proteins. Furthermore, significant folding was observed in the presence of negatively charged lipids and detergents, but not in zwitterionic or neutral lipids or detergents. Absorption onto a surface followed by dehydration stimulated it to fold into a helical structure, as it did when the aqueous solution was replaced by nonaqueous solvents. Hydration of the dehydrated folded protein was accompanied by complete unfolding. These results support the identification of MEG-14 as a classic intrinsically disordered protein, and open the possibility of its interaction/folding with different partners and factors being related to multifunctional roles and states within the host

Symposium The future of informal care [Symposium De toekomst van de informele zorg]

Due to the reform of long term care in 2015, there is growing concern about whether groups at risk receive the care they need. People in need of care have to rely more on help from their social network. The increased need for informal care requires resilience and organizational skills of families, but also of volunteers, professionals and employers. What does this mean for the provision of informal care in the next decennia? The symposium ‘The future of informal care’, organized on January 26 2017 by the National Institute for Social Research and the Institute for Societal Resilience of the Vrije Universiteit, addressed possible answers to this question. In her inaugural speech Alice de Boer discussed social inequality as possible determinant and outcome of informal care. Some conclusions: Until 2050 the absolute number of 75-plus doubled to about 3 million persons, but the number of informal caregivers will decrease. In addition to the importance of social and economic resources (the ‘have & have-nots’), the ability to arrange care (the ‘can & can-nots’) gains importance. Almost half of the older employers provides informal care just before retirement. Flexibility in working hours and work location facilitates combining work and care, but about half of the employers indicates that partial retirement and working at home are no options. Informal caregivers and professionals often provide care from comparable perspectives and identities. Addressing similarities rather than differences improves their chances for collaboration. The number of adult children providing household care to older parents increased between 2002 and 2014. This suggests an increase in family solidarity, but current reform policies may increase the gender inequality in caregiving families. Spouses and children remain primary caregivers in the future, preferably supported by many different types of caregivers. Not everybody has the capabilities to organize and direct such a large care network. Providing informal care increases the risk for overburden and absence at work or education. Informal caregivers at risk remain, also in the future, women, spouses, migrants, and younger carers