383 research outputs found
The Correlation Between Reading Comprehension and Writing Ability of the Second Year Students of Sman 1 Muaro Sentajo Teluk Kuantan in Recount Texts
The objective of this research is to find out the level of students\u27 ability in reading comprehension and writing ability in recount texts and the correlation between those variables of the second year students of SMAN 1 Muaro Sentajo. The sample of this research was class XI IPS 2 which consist 25 students. The data were collected by using two kinds of test, reading comprehension and written test. The result of this research showed that the students got good level with the average score 73.28 in reading comprehension, and in writing the students got good level with the average score 76.12. The result of this research proved that there is a positive correlation between reading comprehension and writing ability on recount texts. The rxy distribution of coefficient correlation is 0.8. It means that the correlation was in a high level. So, Ha (alternative hypothesis) of this research is accepted, and null hypothesis (Ho) is rejected. Is there any difference between students\u27 reading and writing score? So, the researcher try to find out students\u27 reading and writing score and their correlation. Finally, the researcher suggests for the teacher, they should have some efforts to develop the students\u27 motivation and encourage them to practice their reading comprehension and writing ability in recount texts
Direct writing of ferroelectric domains on the x- and y-faces of lithium niobate using a continuous wave ultraviolet laser
Ferroelectric domain reversal has been achieved by scanning a tightly focused, strongly absorbed ultraviolet laser beam across the x- and y-faces of lithium niobate crystals. The domains were investigated by piezoresponse force microscopy. The emergence and width of any domain was found to depend on the scanning direction of the irradiating laser beam with respect to the polar z-axis. Full width and half width domains or no domain formation at all could be achieved for scanning along specific directions. We interpret the results by a direct correlation between the local temperature gradient and the resulting polarization direction
Strain engineering in graphene by laser irradiation
We demonstrate that the Raman spectrum of graphene on lithium niobate can be controlled locally by continuous exposure to laser irradiation. We interpret our results in terms of changes to doping and mechanical strain and show that our observations are consistent with light-induced gradual strain relaxation in the graphene layer
Precision nanoscale domain engineering of lithium niobate via UV laser induced inhibition of poling
Continuous wave ultraviolet (UV) laser irradiation at lambda=244 nm on the +z face of undoped and MgO doped congruent lithium niobate single crystals has been observed to inhibit ferroelectric domain inversion. The inhibition occurs directly beneath the illuminated regions, in a depth greater than 100 nm during subsequent electric field poling of the crystal. Domain inhibition was confirmed by both differential domain etching and piezoresponse force microscopy. This effect allows the formation of arbitrarily shaped domains in lithium niobate and forms the basis of a high spatial resolution micro-structuring approach when followed by chemical etching
Locally erasable couplers for optical device testing in silicon on insulator
Wafer scale testing is critical to reducing production costs and increasing production yield. Here we report a method that allows testing of individual optical components within a complex optical integrated circuit. The method is based on diffractive grating couplers, fabricated using lattice damage induced by ion implantation of germanium. These gratings can be erased via localised laser annealing, which is shown to reduce the outcoupling efficiency by over 20 dB after the device testing is completed. Laser annealing was achieved by employing a CW laser, operating at visible wavelengths thus reducing equipment costs and allowing annealing through thick oxide claddings. The process used also retains CMOS compatibility
Demyelination and axonal preservation in a transgenic mouse model of Pelizaeus-Merzbacher disease
It is widely thought that demyelination contributes to the degeneration of axons and, in combination with acute inflammatory injury, is responsible for progressive axonal loss and persistent clinical disability in inflammatory demyelinating disease. In this study we sought to characterize the relationship between demyelination, inflammation and axonal transport changes using a Plp1-transgenic mouse model of Pelizaeus-Merzbacher disease. In the optic pathway of this non-immune mediated model of demyelination, myelin loss progresses from the optic nerve head towards the brain, over a period of months. Axonal transport is functionally perturbed at sites associated with local inflammation and 'damaged' myelin. Surprisingly, where demyelination is complete, naked axons appear well preserved despite a significant reduction of axonal transport. Our results suggest that neuroinflammation and/or oligodendrocyte dysfunction are more deleterious for axonal health than demyelination per se, at least in the short ter
Ultra-smooth lithium niobate micro-resonators by surface tension reshaping
Thermal treatment of micro-structured lithium niobate substrates at temperatures close to, but below the melting point, allows surface tension to reshape a preferentially melted surface zone [1] of the crystal to form ultra-smooth single crystal toroidal or spherical structures. Such structures, an example of which is shown in figure 1, are suitable for the fabrication of photonic micro-resonators with low scattering loss. The thermally treated material maintains its single crystal nature after the thermal treatment because the bulk remains solid throughout the process acting as seed during the recrystallization process which takes place during the cooling stage. The single crystal nature of the reshaped material has been verified by piezoresponse force microscopy, Raman spectroscopy and chemical etching. The inherent properties of lithium niobate crystals (optically nonlinear, piezoelectric and electro-optic) makes the resultant micro-resonator extremely suitable for sensing applications, for the production of micro-lasers (if doped with Er or Nd), for nonlinear frequency generation and finally for switching/modulation and tunable spectral filtering in optical telecommunications. The transformation of the initial surface micro-structures to the resulting resonator structure is a temperature dependent process as the surface tension acts on the surface melted layer of the crystal, Experimental investigation and modelling of the thermal treatment as well as investigation of the performance of these microresonators is underway to establish full control of the fabrication process for practical applications
Managing the symptoms of neuropathic pain: An exploration of patients' experiences
The debilitating effects of chronic neuropathic pain on everyday life are considerable but little is known about how individual sufferers manage these effects. Virtually nothing is known about what patients prefer, what measures they take themselves, when, or in what combinations. The aim of this study was to explore patients’ reports of how they managed their neuropathic pain symptoms. Three focus groups including 10 participants were used to generate qualitative data on both individual and shared experiences of managing their symptoms of neuropathic pain. Discussions were recorded and transcribed verbatim. Data were analysed using thematic analysis, identifying categories and broader themes of importance to patients. The most common management strategy was the use of conventional medications, often associated with poor effectiveness and unpleasant side-effects. Complementary and alternative medicine was ineffective but many found resting or retreating helpful. They exhibited a repeated cycle of seeking help to manage the pain, with each unsuccessful attempt followed by new attempts. Some had tried to accept their pain, but there was insufficient psychological, social, emotional and practical support to allow them to do this successfully. This exploratory study provides a basis from which to develop a larger study to validate and extend the findings. Other issues meriting research are the effectiveness of cognitive behavioural therapies for those with neuropathic pain; and an exploration and subsequent evaluation of different types of social, practical and emotional support needed to help live with neuropathic pain
Susceptibility to tuberculosis is associated with variants in the ASAP1 gene encoding a regulator of dendritic cell migration
Human genetic factors predispose to tuberculosis (TB). We studied 7.6 million genetic variants in 5,530 people with pulmonary TB and in 5,607 healthy controls. In the combined analysis of these subjects and the follow-up cohort (15,087 TB patients and controls altogether), we found an association between TB and variants located in introns of the ASAP1 gene on chromosome 8q24 (P = 2.6 × 10−11 for rs4733781; P = 1.0 × 10−10 for rs10956514). Dendritic cells (DCs) showed high ASAP1 expression that was reduced after Mycobacterium tuberculosis infection, and rs10956514 was associated with the level of reduction of ASAP1 expression. The ASAP1 protein is involved in actin and membrane remodeling and has been associated with podosomes. The ASAP1-depleted DCs showed impaired matrix degradation and migration. Therefore, genetically determined excessive reduction of ASAP1 expression in M. tuberculosis–infected DCs may lead to their impaired migration, suggesting a potential mechanism of predisposition to TB
Ordered nano-scale domains in lithium niobate single crystals via phase-mask assisted all-optical poling
We report the formation of directionally-ordered nanoscale surface domains on the +z face of undoped congruent lithium niobate single crystals by using UV illumination through a phase mask with an energy fluence between ~90mj/cm2 and 150 mJ/cm2 at lambda = 266 nm. We clearly show here that the UV-induced surface ferroelectric domains nucleate and then propagate along the maxima of laser intensity produced by the phase mask, thus enabling a degree of control over this all-optical poling process. Acid etching of the illuminated crystal faces was employed to reveal the induced domain nature and the spatial structure of the formed nanoscale domains
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