Contribution of organic farming to conserving and improving biodiversity in Germany avi-fauna as an example

Although it is the aim of organic farming to increase biodiversity, there is little information about the impact of organic farming on birds. From 2001 to 2003, the number of breeding birds was recorded annually on the organic experimental farm of the Institute of Organic Farming (600 ha), and on adjacent conventional and organic farms (60 ha and 40 ha) in Northern Germany. The number of skylark (Alauda arvensis) territories increased considerably after the conversion from conventional to organic farming on the premises of the Institute. Their number remained unvaried on the conventional farm. The highest density of skylark territories was found on the farm which has been under organic management for many years. The number of yellowhammer (Emberiza citronella) territories fluctuated largely in relation to the availability of field margin strips, both on conventional and organic land. During the breeding season aerial hunters (swallows and swifts) and raptors significantly preferred organic fields. Outside the breeding season, densities of raptors (in autumn and in winter), seed-eating birds (in autumn) and insect-eating birds (in autumn) were significantly higher on organic than on conventional fields

Formal conserved quantities for isothermic surfaces

Isothermic surfaces in $S^n$ are characterised by the existence of a pencil $\nabla^t$ of flat connections. Such a surface is special of type $d$ if there is a family $p(t)$ of $\nabla^t$-parallel sections whose dependence on the spectral parameter $t$ is polynomial of degree $d$. We prove that any isothermic surface admits a family of $\nabla^t$-parallel sections which is a formal Laurent series in $t$. As an application, we give conformally invariant conditions for an isothermic surface in $S^3$ to be special.Comment: 13 page

Dynamic visualization of membrane-inserted fraction of pHluorin-tagged channels using repetitive acidification technique

<p>Abstract</p> <p>Background</p> <p>Changes in neuronal excitability, synaptic efficacy and generally in cell signaling often result from insertion of key molecules into plasma membrane (PM). Many of the techniques used for monitoring PM insertion lack either spatial or temporal resolution.</p> <p>Results</p> <p>We improved the imaging method based on time-lapse total internal reflection fluorescence (TIRF) microscopy and pHluorin tagging by supplementing it with a repetitive extracellular acidification protocol. We illustrate the applicability of this method by showing that brief activation of NMDA receptors ("chemical LTP") in cultured hippocampal neurons induced a persistent PM insertion of glutamate receptors containing the pHluorin-tagged GluR-A(flip) subunits.</p> <p>Conclusion</p> <p>The repetitive acidification technique provides a more accurate way of monitoring the PM-inserted fraction of fluorescently tagged molecules and offers a good temporal and spatial resolution.</p

Elevated tau and interleukin-6 concentrations in adults with obstructive sleep apnea

The article of record as published may be found at http://dx.doi.org/10.1016/j.sleep.2017.11.1121Obstructive sleep apnea (OSA) is characterized by apneas and hypopneas that result in hypoxia, cerebral hypoperfusion, endothelial dysfunction, inflammation, and oxidative stress. These pathophysiologic processes likely contribute to neuronal damage. Tau is a protein that stabilizes microtubules and, along with amyloid beta (Ab), is associated with neurodegenerative processes. We sought to determine if tau and other biomarkers of inflammation were related to OSA severity. Concentrations of tau, Ab40, Ab42, c-reactive protein (CRP), TNF-a, interleukin (IL)-6, and IL-10 were measured in blood and compared between participants with moderate-severe OSA (n 1⁄4 28), those with mild OSA (n 1⁄4 22), and healthy controls (n 1⁄4 24). The cohort included relatively young, primarily male active duty military personnel without a history of traumatic brain injury or neurodegenerative disease. Total biomarker concentrations were determined from plasma samples using an ultra-sensitive detection method, SimoaTM, and CRP was assayed by ELISA. Total tau and IL-6 concentrations were elevated in participants with moderate-severe OSA, with a mean apnea-hypopnea index (AHI) of 26.1/h, compared to those with mild OSA (mean AHI 8.6/h) and healthy controls (mean AHI 2.1/h). Tau concentrations were also significantly correlated with the AHI (r 1⁄4 0.342, p 1⁄4 0.004). Our findings show that tau is elevated in the blood of young patients with moderate-severe OSA, suggesting that this degree of sleep-disordered breathing is a contributing factor in the development of neurodegenerative disorders. The finding of increased IL-6 further suggests that inflammatory biomarkers are present early in the course of this chronic disease

The PT-symmetric brachistochrone problem, Lorentz boosts and non-unitary operator equivalence classes

The PT-symmetric (PTS) quantum brachistochrone problem is reanalyzed as quantum system consisting of a non-Hermitian PTS component and a purely Hermitian component simultaneously. Interpreting this specific setup as subsystem of a larger Hermitian system, we find non-unitary operator equivalence classes (conjugacy classes) as natural ingredient which contain at least one Dirac-Hermitian representative. With the help of a geometric analysis the compatibility of the vanishing passage time solution of a PTS brachistochrone with the Anandan-Aharonov lower bound for passage times of Hermitian brachistochrones is demonstrated.Comment: 12 pages, 2 figures, strongly extended versio

Generalized isothermic lattices

We study multidimensional quadrilateral lattices satisfying simultaneously two integrable constraints: a quadratic constraint and the projective Moutard constraint. When the lattice is two dimensional and the quadric under consideration is the Moebius sphere one obtains, after the stereographic projection, the discrete isothermic surfaces defined by Bobenko and Pinkall by an algebraic constraint imposed on the (complex) cross-ratio of the circular lattice. We derive the analogous condition for our generalized isthermic lattices using Steiner's projective structure of conics and we present basic geometric constructions which encode integrability of the lattice. In particular, we introduce the Darboux transformation of the generalized isothermic lattice and we derive the corresponding Bianchi permutability principle. Finally, we study two dimensional generalized isothermic lattices, in particular geometry of their initial boundary value problem.Comment: 19 pages, 11 figures; v2. some typos corrected; v3. new references added, higlighted similarities and differences with recent papers on the subjec