Patterning and switching of nano-size ferroelectric memory cells

A "top-down" approach using a-beam lithography and a "bottom-up" one using self-assembly methods were used to fabricate ferroelelectric Pb(Zr,Ti)O-3, SrBi2Ta2O9 and BaTiO3 nanostructures with lateral sizes in the range of 30 nm to 100 nm. Switching of single sub-100 nm cells was achieved and piezoelectric hysteresis loops were recorded using a scanning force microscope working in piezoresponse mode. The piezoelectricity and its hysteresis acquired for 100 nm PZT cells demonstrate that a further decrease in lateral size under 100 nm appears to be possible and that the size effects are not fundamentally limiting on increase density of non-volatile ferroelectric memories in the Gbit range.

Coupled Effects of a Perturbation in a Complex Structure Observed with SDO/AIA, SDO/HMI and ROSA/HARDcam

We study properties of intensity fluctuations in NOAA Active Region 11250 observed on 13 July 2011 starting at UT 13:32. Included are data obtained in the EUV bands of the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory (SDO/AIA) as well as nearly simultaneous observations of the chromosphere made, at much higher spatial and temporal resolution, with the Rapid Oscillations in the Solar Atmosphere (ROSA) and Hydrogen-Alpha Rapid Dynamics camera (HARDcam) systems at the Dunn Solar Telescope. A complex structure seen in both the ROSA/HARDcam and SDO data sets comprises a system of loops extending outward from near the boundary of the leading sunspot umbra. It is visible in the ROSA Ca II K and HARDcam Hα images, as well as the SDO 304 Å, 171 Å and 193 Å channels, and it thus couples the chromosphere, transition region and corona. In the ground-based images the loop structure is 4.1 Mm long. Some 17.5 Mm, can be traced in the SDO/AIA data. The chromospheric emissions observed by ROSA and HARDcam appear to occupy the inner, and apparently cooler and lower, quarter of the loop. We compare the intensity fluctuations of two points within the structure. From alignment with SDO/HMI images we identify a point "A" near the loop structure, which sits directly above a bipolar magnetic feature in the photosphere. Point "B" is characteristic of locations within the loops that are visible in both the ROSA/HARDcam and the SDO/AIA data. The intensity traces for point A are quiet during the first part of the data string. At time ~ 19 min they suddenly begin a series of impulsive brightenings. In the 171 Å and 193 Å coronal lines the brightenings are localized impulses in time, but in the transition region line at 304 Å they are more extended in time. The intensity traces in the 304 Å line for point B shows a quasi-periodic signal that changes properties at about 19 min. The wavelet power spectra are characterized by two periodicities. A 6.7 min period extends from the beginning of the series until about 25 minutes, and another signal with period ~3 min starts at about 20 min. The 193 Å power spectrum has a characteristic period of 5 min, before the 20 min transition and a 2.5 min periodicity afterward. In the case of HARDcam Hα data a localized 4 min periodicity can be found until about 7 min, followed by a quiet regime. After ~20 min a 2.3 min periodicity appears. Interestingly a coronal loop visible in the 94 Å line that is centrally located in the AR, running from the leading umbra to the following polarity, at about time 20 min undergoes a strong brightening beginning at the same moment all along 15 Mm of its length. The fact that these different signals all experience a clear-cut change at time about 20 min suggests an underlying organizing mechanism. Given that point A has a direct connection to the photospheric magnetic bipole, we conjecture that the whole extended structure is connected in a complex manner to the underlying magnetic field. The periodicities in these features may favor the wave nature rather than upflows and interpretations will be discussed.

pLR-HL: a novel amphibian Bowman-Birk-type trypsin inhibitor from the skin secretion of the broad-folded frog, Hylarana latouchii

In this study, we report a novel heptadecapeptide (LIGGCWTKSIPPKPCLV) of the pLR/ranacyclin family, named pLR-HL, whose structure was deduced from its biosynthetic precursor-encoding cDNA cloned from the skin secretion-derived cDNA library of the broad-folded frog, Hylarana latouchii, by employing a "shotgun" cloning technique. It contains a disulphide loop between Cys5 and Cys15 which is consistent with Bowman-Birk-type protease inhibitors. The primary structure of pLR-HL deduced from the cDNA sequence was confirmed by fractionating the skin secretion using reverse phase HPLC and subsequent analysis using MALDI-TOF mass spectrometry and LC/MS/MS fragmentation sequencing. On the basis of the establishment of unequivocal amino acid sequence, a synthetic replicate was synthesised by solid-phase Fmoc chemistry, and it displayed a moderately potent trypsin inhibition with a Ki of 143 nM. The substitution of Lys-8 by Phe (Phe8 -pLR-HL) resulted in abolition of trypsin inhibition but generation of modest inhibition on chymotrypsin with a Ki of 2.141 μM. Additionally, both the disulphide loops of pLR-HL and Phe8 -pLR-HL were synthesised and tested. Both of the catalytic loops retained similar inhibitory potencies towards trypsin or chymotrypsin in comparison with the original intact molecules. Thus, the replacement of reactive site residues could alter the specificity of these protease inhibitors, while the canonical reactive loop alone can independently constitute biologically-active moiety.

PS1-10bzj: A Fast, Hydrogen-poor Superluminous Supernova in a Metal-poor Host Galaxy

We present observations and analysis of PS1-10bzj, a superluminous supernova (SLSN) discovered in the Pan-STARRS Medium Deep Survey at a redshift z = 0.650. Spectroscopically, PS1-10bzj is similar to the hydrogen-poor SLSNe 2005ap and SCP 06F6, though with a steeper rise and lower peak luminosity (M bol ~= -21.4 mag) than previous events. We construct a bolometric light curve, and show that while PS1-10bzj's energetics were less extreme than previous events, its luminosity still cannot be explained by radioactive nickel decay alone. We explore both a magnetar spin-down and circumstellar interaction scenario and find that either can fit the data. PS1-10bzj is located in the Extended Chandra Deep Field South and the host galaxy is imaged in a number of surveys, including with the Hubble Space Telescope. The host is a compact dwarf galaxy (MB ≈ -18 mag, diameter

PS1-10afx at z = 1.388: Pan-STARRS1 Discovery of a New Type of Superluminous Supernova

We present the Pan-STARRS1 discovery of PS1-10afx, a unique hydrogen-deficient superluminous supernova (SLSN) at redshift z = 1.388. The light curve peaked at z P1 = 21.7 mag, making PS1-10afx comparable to the most luminous known SNe, with Mu = -22.3 mag. Our extensive optical and near-infrared observations indicate that the bolometric light curve of PS1-10afx rose on the unusually fast timescale of ~12 days to the extraordinary peak luminosity of 4.1 × 1044 erg s-1 (M bol = -22.8 mag) and subsequently faded rapidly. Equally important, the spectral energy distribution is unusually red for an SLSN, with a color temperature of ~6800 K near maximum light, in contrast to previous hydrogen-poor SLSNe, which are bright in the ultraviolet (UV). The spectra more closely resemble those of a normal SN Ic than any known SLSN, with a photospheric velocity of ~11, 000 km s-1 and evidence for line blanketing in the rest-frame UV. Despite the fast rise, these parameters imply a very large emitting radius (gsim 5 × 1015 cm). We demonstrate that no existing theoretical model can satisfactorily explain this combination of properties: (1) a nickel-powered light curve cannot match the combination of high peak luminosity with the fast timescale; (2) models powered by the spindown energy of a rapidly rotating magnetar predict significantly hotter and faster ejecta; and (3) models invoking shock breakout through a dense circumstellar medium cannot explain the observed spectra or color evolution. The host galaxy is well detected in pre-explosion imaging with a luminosity near L*, a star formation rate of ~15 M ⊙ yr-1, and is fairly massive (~2 × 1010 M ⊙), with a stellar population age of ~108 yr, also in contrast to the young dwarf hosts of known hydrogen-poor SLSNe. PS1-10afx is distinct from known examples of SLSNe in its spectra, colors, light-curve shape, and host galaxy properties, suggesting that it resulted from a different channel than other hydrogen-poor SLSNe.

Performance assessment of cascade control loopswith non-Gaussian disturbances using entropy information

Cascade control is one of the routinely used control strategies in industrial processes because it can dramatically improve the performance of single-loop control, reducing both the maximum deviation and the integral error of the disturbance response. Currently, many control performance assessment methods of cascade control loops are developed based on the assumption that all the disturbances are subject to Gaussian distribution. However, in the practical condition, several disturbance sources occur in the manipulated variable or the upstream exhibits nonlinear behaviors. In this paper, a general and effective index of the performance assessment of the cascade control system subjected to the unknown disturbance distribution is proposed. Like the minimum variance control (MVC) design, the output variances of the primary and the secondary loops are decomposed into a cascade-invariant and a cascade-dependent term, but the estimated ARMA model for the cascade control loop based on the minimum entropy, instead of the minimum mean squares error, is developed for non-Gaussian disturbances. Unlike the MVC index, an innovative control performance index is given based on the information theory and the minimum entropy criterion. The index is informative and in agreement with the expected control knowledge. To elucidate wide applicability and effectiveness of the minimum entropy cascade control index, a simulation problem and a cascade control case of an oil refinery are applied. The comparison with MVC based cascade control is also included.

Magnetic Characteristics of a High-layer-number NiFe/FeMn Multilayer

We report the static & dynamic magnetic characteristics of a high-layer-number NiFe/FeMn multilayer test structure with potential applications in broadband absorber and filter devices. To allow fine control over the absorption linewidths and to understand the mechanisms governing the resonances in a tailored structure similar to that expected to be used in real world applications, the multilayer was intentionally designed to have layer thickness and interface roughness variations. Magnetometry measurements show the sample has complex hysteresis loops with features consistent with single ferromagnetic film reversals. Structural characterisation by transmission electron microscopy allows us to correlate the magnetic properties with structural features. Analysis of resonance frequencies from broadband ferromagnetic resonance measurements as a function of field magnitude and orientation provide values of the local exchange bias, rotatable anisotropy, and uniaxial anisotropy fields for specific layers in the stack and explain the observed mode softening. The linewidths of the multilayer are adjustable around the bias field, approaching twice that seen at larger fields, allowing control over the bandwidth of devices formed from the structure.

Towards a Cyber-physical Resilience Framework for Smart Grids

As modern power grids move towards becoming a smart grid, there is an increasing reliance on the data that is transmitted and processed by ICT systems. This reliance introduces new digital attack vectors. Many of the proposed approaches that aim to address this problem largely focus on applying well-known ICT security solutions. However, what is needed are approaches that meet the complex concerns of the smart grid as a cyber-physical system. Furthermore, to support the automatic control loops that exist in a power grid, similarly automatic security and resilience mechanisms are needed that rely on minimal operator intervention. The research proposed in this paper aims to develop a framework that ensures resilient smart grid operation in light of successful cyber-attacks.

Protocolized versus non-protocolized weaning for reducing the duration of invasive mechanical ventilation in newborn infants: review

Background
Mechanical ventilation is a life-saving intervention for critically ill newborn infants with respiratory failure admitted to a neonatal intensive care unit (NICU). Ventilating newborn infants can be challenging due to small tidal volumes, high breathing frequencies, and the use of uncuffed endotracheal tubes. Mechanical ventilation has several short-term, as well as long-term complications. To prevent complications, weaning from the ventilator is started as soon as possible. Weaning aims to support the transfer from full mechanical ventilation support to spontaneous breathing activity.

Objectives
To assess the efficacy of protocolized versus non-protocolized ventilator weaning for newborn infants in reducing the duration of invasive mechanical ventilation, the duration of weaning, and shortening the NICU and hospital length of stay. To determine efficacy in predefined subgroups including: gestational age and birth weight; type of protocol; and type of protocol delivery. To establish whether protocolized weaning is safe and clinically effective in reducing the duration of mechanical ventilation without increasing the risk of adverse events.

Search methods
We searched the Cochrane Central Register of Controlled trials (CENTRAL; the Cochrane Library; 2015, Issue 7); MEDLINE In-Process and other Non-Indexed Citations and OVID MEDLINE (1950 to 31 July 2015); CINAHL (1982 to 31 July 2015); EMBASE (1988 to 31 July 2015); and Web of Science (1990 to 15 July 2015). We did not restrict language of publication. We contacted authors of studies with a subgroup of newborn infants in their study, and experts in the field regarding this subject. In addition, we searched abstracts from conference proceedings, theses, dissertations, and reference lists of all identified studies for further relevant studies.

Selection criteria
Randomized, quasi-randomized or cluster-randomized controlled trials that compared protocolized with non-protocolized ventilator weaning practices in newborn infants with a gestational age of 24 weeks or more, who were enrolled in the study before the postnatal age of 28 completed days after the expected date of birth.

Data collection and analysis
Four authors, in pairs, independently reviewed titles and abstracts identified by electronic searches. We retrieved full-text versions of potentially relevant studies.

Main results
Our search yielded 1752 records. We removed duplicates (1062) and irrelevant studies (843). We did not find any randomized, quasi-randomized or cluster-randomized controlled trials conducted on weaning from mechanical ventilation in newborn infants. Two randomized controlled trials met the inclusion criteria on type of study and type of intervention, but only included a proportion of newborns. The study authors could not provide data needed for subgroup analysis; we excluded both studies.

Authors' conclusions
Based on the results of this review, there is no evidence to support or refute the superiority or inferiority of weaning by protocol over non-protocol weaning on duration of invasive mechanical ventilation in newborn infants.

Self-regulated Shocks in Massive Star Binary Systems

In an early-type, massive star binary system, X-ray bright shocks result from the powerful collision of stellar winds driven by radiation pressure on spectral line transitions. We examine the influence of the X-rays from the wind-wind collision shocks on the radiative driving of the stellar winds using steady-state models that include a parameterized line force with X-ray ionization dependence. Our primary result is that X-ray radiation from the shocks inhibits wind acceleration and can lead to a lower pre-shock velocity, and a correspondingly lower shocked plasma temperature, yet the intrinsic X-ray luminosity of the shocks, L X, remains largely unaltered, with the exception of a modest increase at small binary separations. Due to the feedback loop between the ionizing X-rays from the shocks and the wind driving, we term this scenario as self-regulated shocks. This effect is found to greatly increase the range of binary separations at which a wind-photosphere collision is likely to occur in systems where the momenta of the two winds are significantly different. Furthermore, the excessive levels of X-ray ionization close to the shocks completely suppress the line force, and we suggest that this may render radiative braking less effective. Comparisons of model results against observations reveal reasonable agreement in terms of log (L X/L bol). The inclusion of self-regulated shocks improves the match for kT values in roughly equal wind momenta systems, but there is a systematic offset for systems with unequal wind momenta (if considered to be a wind-photosphere collision).

Ultra Thin Resistively Loaded FSS Absorber For Polarisation Independent Operation at Large Incident Angles

In this paper we report on a resistively loaded Frequency Selective Surface (FSS) absorber design which is insensitive to the polarization of microwave signals incident at angles of 45o ± 5o. The metal backed periodic structure is composed of an array of conductive rectangular loops, each loaded with a resistor at the center of the four sides. The geometry of the absorber and the resistance value of the vertical and horizontal resistor pairs are carefully chosen so that the structure presents a real impedance of 377 Ω at the center operating frequency for both TE and TM polarized waves incident at 45o. Numerical predictions of the electromagnetic scattering from three different absorbers, designed to work at X-band, are used to investigate the effect of thickness and resistance value on the reflectivity bandwidth and angular sensitivity.

Local probing of ferroelectric and ferroelastic switching through stress-mediated piezoelectric spectroscopy

Strain effects have a significant role in mediating classic ferroelectric behavior such as polarization switching and domain wall dynamics. These effects are of critical relevance if the ferroelectric order parameter is coupled to strain and is therefore, also ferroelastic. Here, switching spectroscopy piezoresponse force microscopy (SS-PFM) is combined with control of applied tip pressure to exert direct control over the ferroelastic and ferroelectric switching events, a modality otherwise unattainable in traditional PFM. As a proof of concept, stress-mediated SS-PFM is applied toward the study of polarization switching events in a lead zirconate titanate thin film, with a composition near the morphotropic phase boundary with co-existing rhombohedral and tetragonal phases. Under increasing applied pressure, shape modification of local hysteresis loops is observed, consistent with a reduction in the ferroelastic domain variants under increased pressure. These experimental results are further validated by phase field simulations. The technique can be expanded to explore more complex electromechanical responses under applied local pressure, such as probing ferroelectric and ferroelastic piezoelectric nonlinearity as a function of applied pressure, and electro-chemo-mechanical response through electrochemical strain microscopy.

Multi-wavelength observations of Proxima Centauri

Aims: We report simultaneous observations of the nearby flare star Proxima Centauri with VLT/UVES and XMM-Newton over three nights in March 2009. Our optical and X-ray observations cover the star's quiescent state, as well as its flaring activity and allow us to probe the stellar atmospheric conditions from the photosphere into the chromosphere, and then the corona during its different activity stages. Methods: Using the X-ray data, we investigate variations in coronal densities and abundances and infer loop properties for an intermediate-sized flare. The optical data are used to investigate the magnetic field and its possible variability, to construct an emission line list for the chromosphere, and use certain emission lines to construct physical models of Proxima Centauri's chromosphere. Results: We report the discovery of a weak optical forbidden Fe xiii line at 3388 Å during the more active states of Proxima Centauri. For the intermediate flare, we find two secondary flare events that may originate in neighbouring loops, and discuss the line asymmetries observed during this flare in H i, He i, and Ca ii lines. The high time-resolution in the Hα line highlights strong temporal variations in the observed line asymmetries, which re-appear during a secondary flare event. We also present theoretical modelling with the stellar atmosphere code PHOENIX to construct flaring chromospheric models. Based on observations collected at the European Southern Observatory, Paranal, Chile, 082.D-0953A and on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member states and NASA.Full Table 6 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/534/A133

X-Ray Emission from the Super-Earth Host GJ 1214

Stellar activity can produce large amounts of high-energy radiation, which is absorbed by the planetary atmosphere leading to irradiation-driven mass loss. We present the detection and an investigation of high-energy emission in a transiting super-Earth host system, GJ 1214, based on XMM-Newton observations. We derive an X-ray luminosity of LX = 7.4 × 1025 erg s-1 and a corresponding activity level of log (LX /L bol) ~ -5.3. Further, we determine a coronal temperature of about ~3.5 MK, which is typical for coronal emission of moderately active low-mass stars. We estimate that GJ 1214 b evaporates at a rate of 1.3× 1010 g s-1 and has lost a total of ≈2-5.6 M ⊕.