Characteristics of events with metric-to-decahectometric type II radio bursts associated with CMEs and flares in relation to SEP events

A gradual solar energetic particle (SEP) event is thought to happen when particles are accelerated at a shock due to a fast coronal mass ejection (CME). To quantify what kind of solar eruptions can result in such SEP events, we have conducted detailed investigations on the characteristics of CMEs, solar flares and m-to-DH wavelength type II radio bursts (herein after m-to-DH type II bursts) for SEP-associated and non-SEP-associated events, observed during the period of 1997-2012. Interestingly, 65% of m-to-DH type II bursts associated with CMEs and flares produced SEP events. The SEP-associated CMEs have higher sky-plane mean speed, projection corrected speed, and sky-plane peak speed than those of non-SEP-associated CMEs respectively by 30%, 39%, and 25%, even though the two sets of CMEs achieved their sky-plane peak speeds at nearly similar heights within LASCO field of view. We found Pearson's correlation coefficients between the speeds of CMEs speeds and logarithmic peak intensity of SEP events are cc = 0.62 and cc = 0.58, respectively. We also found that the SEP-associated CMEs are on average of three times more decelerated (-21.52 m/s2) than the non-SEP-associated CMEs (-5.63 m/s2). The SEP-associated m type II bursts have higher frequency drift rate and associated shock speed than those of the non-SEP-associated events by 70% and 25% respectively. The average formation heights of m and DH type II radio bursts for SEP-associated events are lower than for non-SEP-associated events. 93% of SEP-associated events originate from the western hemisphere and 65% of SEP-associated events are associated with interacting CMEs. The obtained results indicate that, at least for the set of CMEs associated with m-to-DH type II bursts, SEP-associated CMEs are more energetic than those not associated with SEPs, thus suggesting that they are effective particle accelerators.Comment: 19 pages, 10 figures, 3 tables, accepted for publication by ApS

Coexpression of adrenomedullin and its receptor component proteins in the reproductive system of the rat during gestation

<p>Abstract</p> <p>Background</p> <p>Adrenomedullin (ADM), a novel vasorelaxant peptide, was found in human/rat ovaries and uteri. Plasma ADM level increases in pregnant women and pregnant rats.</p> <p>Methods</p> <p>The gene expression levels of <it>Adm </it>and its receptor components - <it>Crlr</it>, <it>Ramp1</it>, <it>Ramp2 </it>and <it>Ramp3</it>, the ADM peptide concentration and localization in the rat female reproductive system during gestation were studied by real-time RT-PCR, EIA and immunohistochemical techniques.</p> <p>Results</p> <p>The mRNAs of <it>Adm </it>and its receptor component and ADM were differentially distributed between implantation sites and inter-implantation sites of the pregnant uterus. The day on which vaginal sperm were found was taken to be pregnancy day 1. The <it>Adm </it>mRNA levels in the implantation sites of the uteri in mid- (day 12) and late pregnancy (day 17) were more than 10-fold higher than those in nonpregnancy, pre-implantation (day 3) or early (day 7) pregnancy. ADM was localized in the endometrial stroma with increased immunoreactivity from nonpregnancy to pregnancy. The ADM level and the mRNA levels of <it>Adm</it>, <it>Crlr</it>, <it>Ramp2 </it>and <it>Ramp3 </it>in the corpus luteum all increased in late pregnancy compared with early pregnancy. The gene expression of <it>Adm </it>and it receptor components and intense immunostaining of ADM were also found in the oviduct during pregnancy.</p> <p>Conclusions</p> <p>The gene expressions levels of <it>Adm </it>and its receptor components - <it>Crlr, Ramp1, Ramp2 </it>and <it>Ramp3</it>, and ADM peptide concentration exhibited a spatio-temporal pattern in the rat female reproductive system during gestation and this suggests that ADM may play important roles in gestation.</p

Adrenomedullin in rat follicles and corpora lutea: expression, functions and interaction with endothelin-1

<p>Abstract</p> <p>Background</p> <p>Adrenomedullin (ADM), a novel vasorelaxant peptide, was found in human/rat ovaries. The present study investigated the interaction of ADM and endothelin-1 (ET-1) in follicles and newly formed corpora lutea (CL) and the actions of ADM on progesterone production in CL during pregnancy.</p> <p>Methods</p> <p>The peptide and gene expression level of adrenomedullin in small antral follicles, large antral follicles and CL was studied by real-time RT-PCR and EIA. The effect of ADM treatment on oestradiol production in 5-day follicular culture and on progesterone production from CL of different pregnant stages was measured by EIA. The interaction of ADM and ET-1 in follicles and CL at their gene expression level was studied by real-time RT-PCR.</p> <p>Results</p> <p>In the rat ovary, the gene expression of <it>Adm </it>increased during development from small antral follicles to large antral follicles and CL. In vitro treatment of preantral follicular culture for 5 days with ADM increased oestradiol production but did not affect follicular growth or ovulation rate. The regulation of progesterone production by ADM in CL in culture was pregnancy-stage dependent, inhibitory at early and late pregnancy but stimulatory at mid-pregnancy, which might contribute to the high progesterone production rate of the CL at mid-pregnancy. Moreover, the interaction between ADM and ET-1 at both the production and functional levels indicates that these two vasoactive peptides may form an important local, fine-tuning regulatory system together with LH and prolactin for progesterone production in rat CL.</p> <p>Conclusions</p> <p>As the CL is the major source of progesterone production even after the formation of placenta in rats, ADM may be an important regulator in progesterone production to meet the requirement of pregnancy.</p

The ratchet effect and the transporting islands in the chaotic sea

We study directed transport in a classical deterministic dissipative system. We consider the generic case of mixed phase space and show that large ratchet currents can be generated thanks to the presence, in the Hamiltonian limit, of transporting stability islands embedded in the chaotic sea. Due to the simultaneous presence of chaos and dissipation the stationary value of the current is independent of initial conditions, except for initial states with very small measure.Comment: 5 pages, 6 figure

Not so crystal clear: the structure of the human telomere G-quadruplex in solution differs from that present in a crystal

The structure of human telomere DNA is of intense interest because of its role in the biology of both cancer and aging. The sequence [5′-AGGG(TTAGGG)(3)] has been used as a model for telomere DNA in both NMR and X-ray crystallographic studies, the results of which show dramatically different structures. In Na(+) solution, NMR revealed an antiparallel G-quadruplex structure that featured both diagonal and lateral TTA loops. Crystallographic studies in the presence of K(+) revealed a flattened, propeller-shaped structure featuring a parallel-stranded G-quadruplex with symmetrical external TTA loops. We report the results of biophysical experiments in solution and computational studies that are inconsistent with the reported crystal structure, indicating that a different structure exists in K(+) solutions. Sedimentation coefficients were determined experimentally in both Na(+) and K(+) solutions and were compared with values calculated using bead models for the reported NMR and crystal structures. Although the solution NMR structure accurately predicted the observed S-value in Na(+) solution, the crystal structure predicted an S-value that differed dramatically from that experimentally observed in K(+) solution. The environments of loop adenines were probed by quantitative fluorescence studies using strategic and systematic single-substitutions of 2-aminopurine for adenine bases. Both fluorescence intensity and quenching experiments in K(+) yielded results at odds with quantitative predictions from the reported crystal structure. Circular dichroism and fluorescence quenching studies in the presence of the crowding agent polyethylene glycol showed dramatic changes in the quadruplex structure in K(+) solutions, but not in Na(+) solutions, suggesting that the crystal environment may have selected for a particular conformational form. Molecular dynamics simulations were performed to yield model structures for the K(+) quadruplex form that are consistent with our biophysical results and with previously reported chemical modification studies. These models suggest that the biologically relevant structure of the human telomere quadruplex in K(+) solution is not the one determined in the published crystalline state

Phononics: Manipulating heat flow with electronic analogs and beyond

The form of energy termed heat that typically derives from lattice vibrations, i.e. the phonons, is usually considered as waste energy and, moreover, deleterious to information processing. However, with this colloquium, we attempt to rebut this common view: By use of tailored models we demonstrate that phonons can be manipulated like electrons and photons can, thus enabling controlled heat transport. Moreover, we explain that phonons can be put to beneficial use to carry and process information. In a first part we present ways to control heat transport and how to process information for physical systems which are driven by a temperature bias. Particularly, we put forward the toolkit of familiar electronic analogs for exercising phononics; i.e. phononic devices which act as thermal diodes, thermal transistors, thermal logic gates and thermal memories, etc.. These concepts are then put to work to transport, control and rectify heat in physical realistic nanosystems by devising practical designs of hybrid nanostructures that permit the operation of functional phononic devices and, as well, report first experimental realizations. Next, we discuss yet richer possibilities to manipulate heat flow by use of time varying thermal bath temperatures or various other external fields. These give rise to a plenty of intriguing phononic nonequilibrium phenomena as for example the directed shuttling of heat, a geometrical phase induced heat pumping, or the phonon Hall effect, that all may find its way into operation with electronic analogs.Comment: 24 pages, 16 figures, modified title and revised, accepted for publication in Rev. Mod. Phy

An optimal gap theorem

By solving the Cauchy problem for the Hodge-Laplace heat equation for $d$-closed, positive $(1, 1)$-forms, we prove an optimal gap theorem for K\"ahler manifolds with nonnegative bisectional curvature which asserts that the manifold is flat if the average of the scalar curvature over balls of radius $r$ centered at any fixed point $o$ is a function of $o(r^{-2})$. Furthermore via a relative monotonicity estimate we obtain a stronger statement, namely a `positive mass' type result, asserting that if $(M, g)$ is not flat, then $\liminf_{r\to \infty} \frac{r^2}{V_o(r)}\int_{B_o(r)}\mathcal{S}(y)\, d\mu(y)>0$ for any $o\in M$