Carrier dynamics and infrared-active phonons in c-axis oriented RuSr2_2GdCu2_2O8_8 film

The conductivity spectra of c-axis oriented thin RuSr$_2$GdCu$_2$O$_8$ film on SrTiO$_3$ substrate, prepared by pulsed-laser deposition, are obtained from the analysis of the reflectivity spectra over broad frequency range and temperatures between 10 and 300 K. The free charge carriers are found to be strongly overdamped with their scattering rate (1.0 eV at room temperature) exceeding the plasma frequency (0.55 eV). Four phonon lines are identified in the experimental spectra and assigned to the specific oxygen related in-plane polarized vibrations based on the comparison with the results of a lattice dynamics shell model calculations.Comment: 3 pages, 4 figure

The Disparity in Mental Health Between Two Generations of Internal Migrants (IMs) in China: Evidence from A Nationwide Cross-Sectional Study

Background: Internal migrants (IMs) are a large, vulnerable population in China and are mostly driven by national economic reform. IMs who were born before and after 1980, when the general social and economic reform began to appear in China, are considered to be two separate generations. The generational differences in mental health across IMs remain undocumented. In this study, the intergenerational disparity in IMs’ mental health, using data from a national cross-sectional study, was assessed. Methods: Cross-sectional data from the “National Internal Migrant Dynamic Monitoring Survey 2014” were used. IMs were divided into the “old” or “new” generation, based on their date of birth (before 1980 vs. from 1980 onwards). Mental health includes psychological distress, which was measured using the Kessler Screening Scale for Psychological Distress (K6), and perceived stress, which was measured with the Perceived Stress Scales (PSS-4). Two-level Generalized Linear Mixed Models were performed so as to assess the generation gap and associated factors of each group’s mental health. IM demographics, migration characteristics, and social integration indicators were controlled for when assessing the intergenerational disparity in mental health. Results: A total of 15,999 IMs from eight different cities participated in the survey. New generation migrants accounted for 61.5% (9838/15,999) of the total sample. After controlling for participants’ characteristics, new generation migrants had higher psychological distress scores (βad = 0.084, 95% CI: (0.026,0.193) and higher perceived stress scores (βad = 0.118, 95% CI: 0.029, 0.207) than the older generation. For both generations, factors associated with good mental health included high levels of social integration, personal autonomy, and life satisfaction, as well as self-rated good physical health. For the new generation, the mental health of urban-to-urban IMs (βad = 0.201, 95%CI: 0.009, 0.410) for the K6, βad = 0.241, 95% CI: 0.073, 0.409 for the PSS-4), IMs with a longer migration duration (βad = 0.002, 95% CI: (0.000, 0.003) for the PSS-4) and IMs with a higher annual income (βad = 0.124, 95% CI: (0.029, 0.218) for the K6) was significantly poorer than their counterparts. Conclusions: New-generation migrants’ mental health is worse compared to older IMs. An array of services for addressing these generation-specific needs may facilitate the promotion of mental health among IMs in China

High temperature and vapor pressure deficit aggravate architectural effects but ameliorate non-architectural effects of salinity on dry mass production of tomato

Tomato (Solanum lycopersicum L.) is an important vegetable crop and often cultivated in regions exposed to salinity and high temperatures (HT) which change plant architecture, decrease canopy light interception and disturb physiological functions. However, the long-term effects of salinity and HT combination (S+HT) on plant growth are still unclear. A dynamic functional-structural plant model (FSPM) of tomato was parameterized and evaluated for different levels of S+HT combinations. The evaluated model was used to quantify the contributions of morphological changes (architectural effects) and physiological disturbances (non-architectural effects) on the reduction of shoot dry mass under S+HT. The model predicted architectural variables with high accuracy (>85%), which ensured the reliability of the model analyses. HT enhanced architectural effects but reduced non-architectural effects of salinity on dry mass production. The stronger architectural effects of salinity under HT could not be counterbalanced by the smaller non-architectural effects. Therefore, long-term influences of HT on shoot dry mass under salinity were negative at the whole plant level. Our model analysis highlights the importance of plant architecture at canopy level in studying the plant responses to the environments and shows the merits of dynamic FSPMs as heuristic tools.DF

Understanding wavelength scaling in 19-cell core hollow-core photonic bandgap fibers

First experimental wavelength scaling in 19-cell core HC-PBGF indicates that the minimum loss waveband occurs at longer wavelengths than previously predicted. Record low loss (2.5dB/km) fibers operating around 2µm and gas-purging experiments are also reported

Personalisation of intelligent homecare services adapted to children with motor impairments

Ambient Intelligence could support innovative application domains like motor impairments' detection at the home environment. This research aims to prevent neurodevelopmental disorders through the natural interaction of the children with embedded intelligence daily life objects, like home furniture and toys. Designed system uses an interoperable platform to provide two intelligent interrelated home healthcare services: monitoring of children¿s abilities and completion of early stimulation activities. A set of sensors, which are embedded within the rooms, toys and furniture, allows private data gathering about the child's interaction with the environment. This information feeds a reasoning subsystem, which encloses an ontology of neurodevelopment items, and adapts the service to the age and acquisition of expected abilities. Next, the platform proposes customized stimulation services by taking advantage of the existing facilities at the child's environment. The result integrates Embedded Sensor Systems for Health at Mälardalen University with UPM Smart Home, for adapted services delivery

Intergrating human rights approaches into public health practices and policies to address health needs amongst Rohingya refugees in Bangladesh: a systematic review and meta-ethnographic analysis

Background: The Rohingya people of Myanmar are one of the most persecuted communities in the world and are forced to flee their home to escape conflict and persecution. Bangladesh receives the majority of the Rohingya refugees. On arrival they experience a number of human rights issues and the extent to which human rights approaches are used to inform public health programs is not well documented. The aim of this systematic review was to document human rights- human rights-related health issues and to develop a conceptual human rights framework to inform current policy practice and programming in relation to the needs of Rohingya refugees in Bangladesh. Methods: This systematic review was conducted using the 2015 Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines. Eight computerized databases were searched: Academic Search complete, Embase, CINAHL, JStor, Pubmed, Scopus, SocIndex, and Proquest Central along with grey literature and Google Scholar. Of a total of 752 articles retrieved from the eight databases and 17 studies from grey literature, 31 studies met our inclusion criteria. Results: Using meta-ethnographic synthesis, we developed a model that helps understand the linkages of various human rights and human rights-related health issues of Rohingya refugees. The model highlights how insufficient structural factors, poor living conditions, restricted mobility, and lack of working rights for extended periods of time collectively contribute to poor health outcomes of Rohingya refugees

Scaling and nonscaling finite-size effects in the Gaussian and the mean spherical model with free boundary conditions

We calculate finite-size effects of the Gaussian model in a L\times \tilde L^{d-1} box geometry with free boundary conditions in one direction and periodic boundary conditions in d-1 directions for 2<d<4. We also consider film geometry (\tilde L \to \infty). Finite-size scaling is found to be valid for d3 but logarithmic deviations from finite-size scaling are found for the free energy and energy density at the Gaussian upper borderline dimension d* =3. The logarithms are related to the vanishing critical exponent 1-\alpha-\nu=(d-3)/2 of the Gaussian surface energy density. The latter has a cusp-like singularity in d>3 dimensions. We show that these properties are the origin of nonscaling finite-size effects in the mean spherical model with free boundary conditions in d>=3 dimensions. At bulk T_c in d=3 dimensions we find an unexpected non-logarithmic violation of finite-size scaling for the susceptibility \chi \sim L^3 of the mean spherical model in film geometry whereas only a logarithmic deviation \chi\sim L^2 \ln L exists for box geometry. The result for film geometry is explained by the existence of the lower borderline dimension d_l = 3, as implied by the Mermin-Wagner theorem, that coincides with the Gaussian upper borderline dimension d*=3. For 3<d<4 we find a power-law violation of scaling \chi \sim L^{d-1} at bulk T_c for box geometry and a nonscaling temperature dependence \chi_{surface} \sim \xi^d of the surface susceptibility above T_c. For 2<d<3 dimensions we show the validity of universal finite-size scaling for the susceptibility of the mean spherical model with free boundary conditions for both box and film geometry and calculate the corresponding universal scaling functions for T>=T_c.Comment: Submitted to Physical Review

Contact-induced spin polarization in carbon nanotubes

Motivated by the possibility of combining spintronics with molecular structures, we investigate the conditions for the appearance of spin-polarization in low-dimensional tubular systems by contacting them to a magnetic substrate. We derive a set of general expressions describing the charge transfer between the tube and the substrate and the relative energy costs. The mean-field solution of the general expressions provides an insightful formula for the induced spin-polarization. Using a tight-binding model for the electronic structure we are able to estimate the magnitude and the stability of the induced moment. This indicates that a significant magnetic moment in carbon nanotubes can be observed.Comment: To appear in Phys. Rev. B (2003

Computational Fluid Dynamics Simulations at Micro-Scale Stenosis for Microfluidic Thrombosis Model Characterization

Platelet aggregation plays a central role in pathological thrombosis, preventing healthy physiological blood flow within the circulatory system. For decades, it was believed that platelet aggregation was primarily driven by soluble agonists such as thrombin, adenosine diphosphate and thromboxane A2. However, recent experimental findings have unveiled an intriguing but complementary biomechanical mechanism—the shear rate gradients generated from flow disturbance occurring at sites of blood vessel narrowing, otherwise known as stenosis, may rapidly trigger platelet recruitment and subsequent aggregation. In our Nature Materials 2019 paper [1], we employed microfluidic devices which incorporated micro-scale stenoses to elucidate the molecular insights underlying the prothrombotic effect of blood flow disturbance. Nevertheless, the rheological mechanisms associated with this stenotic microfluidic device are poorly characterized. To this end, we developed a computational fluid dynamics (CFD) simulation approach to systematically analyze the hemodynamic influence of bulk flow mechanics and flow medium. Grid sensitivity studies were performed to ensure accurate and reliable results. Interestingly, the peak shear rate was significantly reduced with the device thickness, suggesting that fabrication of microfluidic devices should retain thicknesses greater than 50 µm to avoid unexpected hemodynamic aberration, despite thicker devices raising the cost of materials and processing time of photolithography. Overall, as many groups in the field have designed microfluidic devices to recapitulate the effect of shear rate gradients and investigate platelet aggregation, our numerical simulation study serves as a guideline for rigorous design and fabrication of microfluidic thrombosis models

Suppression of Quantum Phase Interference in Molecular Magnets Fe&#8328; with Dipolar-Dipolar Interaction

Renormalized tunnel splitting with a finite distribution in the biaxial spin model for molecular magnets is obtained by taking into account the dipolar interaction of enviromental spins. Oscillation of the resonant tunnel splitting with a transverse magnetic field along the hard axis is smeared by the finite distribution which subsequently affects the quantum steps of hysteresis curve evaluated in terms of the modified Landau-Zener model of spin flipping induced by the sweeping field. We conclude that the dipolar-dipolar interaction drives decoherence of quantum tunnelling in molcular magnets Fe&#8328;, which explains why the quenching points of tunnel spliting between odd and even resonant tunnelling predcited theoretically were not observed experimentally.Comment: 5 pages including 3 figure and 1 table. To appear in Physical Review