Main Transition Point Research Articles

The JWST weather report from the nearest brown dwarfs I: multiperiod JWST NIRSpec + MIRI monitoring of the benchmark binary brown dwarf WISE 1049AB

ABSTRACT We report results from 8 h of JWST/MIRI low resolution spectroscopic (LRS) monitoring directly followed by 7 h of JWST/NIRSpec prism spectroscopic monitoring of the benchmark binary brown dwarf WISE 1049AB, the closest, brightest brown dwarfs known. We find water, methane, and CO absorption features in both components, including the 3.3 μm methane absorption feature and a tentative detection of small grain ($\lt $ 1μm) silicate absorption at $\gt $8.5 μm in WISE 1049A. Both components vary significantly ($\gt 1~{{\rm per\ cent}}$), with WISE 1049B displaying larger variations than WISE 1049A. Using K-means clustering, we find three main transition points in wavelength for both components of the binary: (1) change in behaviour at $\sim$2.3 μm coincident with a CO absorption bandhead, (2) change in behaviour at 4.2 μm, close to the CO fundamental band at $\lambda \gt $ 4.4 µm, and (3) change in behaviour at 8.3–8.5 µm, potentially corresponding to silicate absorption. We interpret the light curves observed with both NIRSpec and MIRI as likely stemming from (1) a deep pressure level driving the double-peaked variability seen in WISE 1049B at wavelengths $\lt $2.3 and $\gt $8.5 µm, (2) an intermediate pressure level shaping the light-curve morphology between 2.3 and 4.2 µm, and (3) a higher altitude pressure level producing single-peaked and plateaued light-curve behaviour between 4.2 and 8.5 µm.

Prevalence of medication discrepancies in pediatric patients transferred between hospital wards.

Background Children are more susceptible to harm from medication errors and adverse drug reactions when compared to adults. Such events may occur from medication discrepancies while transitioning patients throughout the healthcare system. Contributing factors include medication discontinuity and lack of information by the healthcare team. Objective To analyze the prevalence of medication discrepancies in transition points of care in a pediatric department. SettingPediatric department of a public hospital in Northeast Brazil. MethodA cross-sectional study was carried out from August 2017 to March 2018. Data collection consisted of the following steps: collection of sociodemographic data, clinical interview with the patient's caregiver, registration of patient prescriptions, and evaluation of medical records. Medication discrepancies were classified as intentional and unintentional. The unintentional medication discrepancies were classified as omission of medication, therapeutic duplicity, and differences in dose, frequency, or route of administration. Main outcomes measureDiscrepancy profile identified at admission, internal transfer and hospital discharge. Results Among the 114 patients included in the study, 85 (74.5%) patients had at least one unintentional medication discrepancy, of which 16 (14.0%) patients presented medication discrepancies at hospital admission, 42 (36.8%) patients at internal transfer, and 52 (45.6%) patients during discharge. Omission of medication represented 20 (74.1%) errors at admission, 26 (37.7%) errors at internal transfer, and 80 (100.0%) errors at hospital discharge. Conclusions The main transition points of care where unintentional discrepancies occurred in the studied pediatric department were at internal transfer and hospital discharge, with omission being the most common type of unintentional discrepancy.

ПЕРІОДИЗАЦІЯ РОЗВИТКУ ІНФОРМАЦІЙНО- ПРОПАГАНДИСТСЬКОГО ЗАБЕЗПЕЧЕННЯ У ВІЙСЬКОВО-МОРСЬКИХ СИЛАХ ЗБРОЙНИХ СИЛ УКРАЇНИ В 1992–2014 РОКАХ

The article substantiates the periodization of formation and development of information and propaganda support in the Ukrainіаn Navy in 1992-2014. It is established that the basis for justifying the periodization of the process of devel- opment of information and propaganda support is its objective connection with the processes of development of the legal framework and the organizational form of the structures that conducted the propaganda. It was the changes in the legal framework and organization of propaganda structures that significantly influ- enced the changes in the development of the subject of study, which served as a basis for selecting their criteria for periodization.The proposed periodization fully takes into account the approaches of Ukrain- ian scientists to the periodization of the development of the Armed Forces of Ukraine, the Ukrainіаn Navy and certain areas of propaganda activity, as well as periods of change in the social and political life of the state. In particular, this study highlights the relationship between the model of information support in the military and the form of government. The author’s periodization most accurately reflects the main transition points in the development of information and propa- ganda support in the Ukrainian Navy. Information and propaganda support in the Ukrainian Navy in 1992-2014 was a transition model from eastern (Soviet) to western. During the study period, 2 attempts were made to bring the model of information support closer to a similar Western model - in 1992-1993 and in 2006-2013. That is, the historically condi- tioned model of model of information support for Ukraine is Western.Separation of the periods of development of the subject of study made it pos- sible to establish specific features of its historical development and focus on the standards of NATO member states, which in the conditions of modern transfor- mations of information and propaganda support in the Armed Forces of Ukraine in the absence of comprehensive historical research in this direction will serve as an important source of experience.

Syrian Refugee Crisis and European Migration Policies: Rise in Xenophobic Rhetoric in Europe

Syrian immigration crisis has been ignored by advanced European countries and the heaviest burden is left to developing border countries. However this ignorance has resulted in more mass influx of immigrants illegally to the borders of European Union with a target of advanced Northern countries. To evaluate the European ignorance to this humanitarian crisis, first Turkey is evaluated as a transition point for all Asian and Middle Eastern immigrants dreaming to live in Europe. By a shocking extend of sea arrivals, Europe have noticed the humanitarian crisis and made a deal with main transition point for immigrants, Turkey. However this deal is a symbol of violation human rights and vaporisation of all European values. So refugee crisis and policy changes in Europe are covered briefly. In conclusion, this position of European countries is argued as related with accelerating social support to xenophobic and Islamophobic rhetoric in politics as to elective results in advanced EU countries.

Poincaré-like approach to Landau theory. II. Simplifying the Landau-deGennes potential for nematic liquid crystals

In a previous paper, we have discussed how the Landau potential (entering in Landau theory of phase transitions) can be simplified using the Poincaré normalization procedure. Here, we apply this approach to the Landau-deGennes functional for the isotropic-nematic transitions, and transitions between different nematic phases, in liquid crystals. We give special attention to applying our method in the region near the main transition point, showing in full detail how this can be done via a suitable simple modification of our Poincaré-like method. We also consider the question if biaxial phases can branch directly off the fully symmetric state; some partial results in this direction are presented.

Forerunning mode transition in a continuous waveguide

We have discovered a forerunning mode transition as the periodic wave changing the state of a uniform continuous waveguide. The latter is represented by an elastic beam initially rested on an elastic foundation. Under the action of an incident sinusoidal wave, the separation from the foundation occurs propagating in the form of a transition wave. The critical displacement is the separation criterion. Under these conditions, the steady-state mode exists with the transition wave speed independent of the incident wave amplitude. We show that such a regime exists only in a bounded domain of the incident wave parameters. Outside this domain, for higher amplitudes, the steady-state mode is replaced by a set of local separation segments periodically emerging at a distance ahead of the main transition point. The crucial feature of this waveguide is that the incident wave group speed is greater than the phase speed. This allows the incident wave to deliver the energy required for the separation. The analytical solution allows us to show in detail how the steady-state mode transforms into the forerunning one. The latter studied numerically turns out to be periodic. As the incident wave amplitude grows the period decreases, while the transition wave speed averaged over the period increases to the group velocity of the wave. As an important part of the analysis, the complete set of solutions is presented for the waves excited by the oscillating or/and moving force acting on the free beam. In particular, an asymptotic solution is evaluated for the resonant wave corresponding to a certain relation between the load's speed and frequency.

Flux of nutrients between the middle and southern Adriatic Sea (Gargano-Split section)

The transect Gargano-Split at the borderline between the middle and southern Adriatic on the Palagruža Sill is exposed to the influences both from the northern and southern Adriatic and is a main transition point for the Adriatic. Thus, water and dissolved inorganic nutrients fluxes between the northern shelf area and the southern deep sea can be estimated at this point. During the Dynamic of the Adriatic in Real Time (DART) project, 12 bottom-mounted Acoustic Doppler Current Profilers (ADCPs) were deployed from November 2005 to September 2006 along the Gargano-Split section. During the same period four different oceanographic cruises were carried out (in November 2005, March, April and July 2006). Hydrographic stations were sampled with the CTD/Rosette to measure physical (temperature, salinity and density) and chemical (oxygen, orthosilicate, orthophosphate and nitrite+nitrate) parameters. Measurements of current velocities allowed estimation of water fluxes and the net nutrient transports were estimated from these and nutrient concentrations. The orthosilicate flux across the transect for inflow and for outflow was higher (except for March) than the nitrite+nitrate and the orthophosphate fluxes. The outflowing nutrient fluxes in the Western Adriatic Current (WAC) were much lower than the total nutrient flux outflow as a large portion of the nutrient flux towards the southern Adriatic was carried by other outflowing waters including North Adriatic Dense Water (NAdDW) flowing along the Italian bottom slope and Middle Adriatic Dense Water (MAdDW) flowing through the deepest passage in the center of the Sill. The July survey provided the first opportunity for direct measurements of total nutrient fluxes across a full basin transect of the central Adriatic. The measurements suggest that the nutrient import and nutrient export were roughly in balance. Modified Levantine Intermediate Water (MLIW) significantly contributed to a total nutrient influx across the transect that was strong enough to counter-balance the nutrient export by the WAC, NAdDW, MAdDW, and other sources.

Understanding bubble hydrodynamics in bubble columns

Compared to conventional gas–liquid bubble columns, gas–liquid columns including both gas and liquid flows have been investigated less due to their complex hydrodynamics and operational difficulties. In this study, simultaneous non-intrusive methods of column shell vibration and pressure fluctuation measurements were coupled with direct photography and image analysis for bubble characterization. Various statistical and frequency analyses were conducted on the acceleration and pressure fluctuations signals to determine their capability of interpreting bubble behavior inside the column. The standard deviation of vibration signals showed less sensitivity to bubble behavior compared to that of pressure fluctuations. The skewness of vibration and pressure fluctuations could detect bubble regime transition points at all studied gas and liquid velocities while vibration and pressure fluctuations kurtosis could only detect the main transition point of the column at a moderate liquid velocity. It was found that besides regular statistical methods, the energy of pressure signals could predict bubble regime transition points successfully. While vibration-based inspection showed more sensitivity to bubble size distribution (similar to the standard deviation of pressure signals), frequency analysis on pressure signals proved to be a strong representative of bubble Sauter mean diameter alteration by liquid flow variation at constant gas velocities. Moreover, by means of energy-based discrete wavelet transformation, we defined the exact pathway of various sub-signal gradual evolutions throughout a wide range of operating conditions of gas and liquid velocities and captured regime transition points accordingly. The proposed methods in this work can be used for non-intrusive hydrodynamic characterization in industrial bubble columns.

Compressibility and thermal expansion coefficients of nanocomposites with amorphous and crystalline polymer matrix

Clay-containing polymeric nanocomposites (CPNC) with polystyrene (PS) or polyamide-6 (PA-6) matrix were studied within T = 300–600 K and P = 0.1–190 MPa. From the Pressure–Volume–Temperature ( PVT) data the derivatives: compressibility, κ, and thermal expansion coefficient, α, were computed as functions of T, P and clay content, w. Dependence of these coefficients on P and T were significantly different for the amorphous PS than for the semi-crystalline PA-6. In the PS plots of κ and α vs. T the presence of secondary transitions, T β/ T g ≈ 0.9 ± 0.1 and T c/ T g = 1.2 ± 0.1, were detected and the clay effect at low T was prominent, affecting the physical aging. The isobaric values of α = α( T) were characterized by nearly T-independent values in the glassy and molten phase, connected by a large transitory region stretching from the ambient pressure values of T g to T c; this region was even more prominent in κ = κ( T). The derivative properties of PA-6 based CPNC were distinctly different. Here, the isobaric κ = κ( T) followed the same dependence on both sides of the melting zone, while the isobaric α = α( T) dependencies were dramatically different for the solid and molten phase; at T < T m α linearly increased with T, after melting its value sharply decreased, and then at T > T m (depending on w and P) either increased or decreased with T. Interpretation of the behavior in the melt and glass is based on the Simha–Somcynsky (S–S) cell-hole theory while that of the semicrystalline state on the Midha–Nanda–Simha–Jain (MNSJ) cell theory. In spite of the nonequilibrium conditions below the main transition point, T g or T m, the theories well predict the observed dependencies.

Bending modulus of lipid bilayers in a liquid-crystalline phase including an anomalous swelling regime estimated by neutron spin echo experiments

Membrane fluctuations of dipalmitoylphosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) were investigated by neutron spin echo spectroscopy. The intermediate structure factor was analyzed in terms of the model proposed by Zilman and Granek (Phys. Rev. Lett. 77, 4788 (1996)), and the bending modulus of lipid bilayers was derived. The hardening of a lipid bilayer upon approaching the main transition point in the anomalous swelling regime was observed, which naturally connects the bending modulus in the gel phase below the main transition temperature.

Developmental regulation in the Schwann cell lineage.

The main developmental stages in the Schwann cell lineage have now been identified (Fig. 1). Most Schwann cells originate in the neural crest and are found in mature nerves as two distinct cells, the non-myelinating and myelinating Schwann cells (Jessen and Mirsky, 1992; Le Douarin et al., 1991). The two Schwann cell variants are probably present in comparable numbers throughout the peripheral nervous system (PNS). The generation of these cells from neural crest cells, involves the formation of two main intermediates, the Schwann cell precursor, typically found in rat nerves at embryo day (E) 14 and 15 (mouse E12 and 13) and the immature Schwann cell, present from E17 (mouse E15) to around birth. At birth, the cells start to differentiate, first along the myelin pathway, with mature non-myelinating cells appearing later. The lineage therefore involves three main transition points, i.e. the transition of crest cells to precursors, of precursors to immature Schwann cells and lastly the final, and largely reversible, formation of the two mature Schwann cell types (Jessen and Mirsky, 1997; 1998; Mirsky and Jessen, 1996).

Phase Transition of Lipid Multilamellar Aqueous Suspension under High Pressure V. Ultrasonic Measurements in Temperature Range from 4th Transition to Main One under High Pressure

The ultrasonic velocity and absorption at single 5 MHz of the DPPC multilamellar containing 25 wt.% water in the temperature range from the 4th transition to the main one have been investigated under several pressures up to about 300 MPa. Four phase transitions were measured as follows: (1) A fluctuation of the DPPC bimembrane density in the vicinity of the main transition point was strongly restricted due to the effect of pressure, and an extremely unsymmetrical form of the absorption peak around the main transition with an increase in pressure beyond 150 MPa was observed, (2) the notable appearance of the absorption peak in the pretransition under 250 MPa was observed although no absorption peak could be detected under pressure of less than 250 MPa, and (3) the changes of the ultrasonic velocity and bulk modulus corresponding to the sub- (or melting-like behavior) and 4th transition were observed distinctly under 295 MPa.