Tendências no desempenho em matemáticas e ciências em 18 países: análise de regressão múltipla de efeitos de coorte no TIMSS 1995-2007

The purpose of this study was to simultaneously examine relationships between teacher quality and instructional time and mathematics and science achievement of 8th grade cohorts in 18 advanced and developing economies. In addition, the study examined changes in mathematics and science performance across the two groups of economies over time using data from the TIMSS 1995-2007 assessments. While economy did not account for variation in mathematics and science achievement, findings from regression analyses indicated significant relationships between school inputs and achievement in both groups of countries across the years. Teaching experience was a strong indicator of mathematics performance in developing countries, while instructional time was mildly related to achievement in both subjects in advanced economies.El objetivo de este estudio fue examinar simultáneamente las relaciones entre la calidad docente y el tiempo de instrucción y los logros en matemáticas y ciencias de una cohorte de 8° grado en 18 economías avanzadas y en desarrollo. Además, el estudio examinó los cambios en el rendimiento en matemáticas y ciencias entre dos grupos de economías a lo largo del tiempo utilizando los datos de las evaluaciones de TIMSS de 1995-2007. Aunque la variable “economía” no mostró variación en los resultados de logros de aprendizaje en matemáticas y ciencias, los análisis de regresión muestran relaciones significativas entre los insumos escolares y logros de aprendizaje en los dos tipos de países a lo largo de los años. La experiencia docente fue un fuerte indicador del rendimiento en matemáticas en los países en desarrollo, mientras que el tiempo de instrucción se relaciona medianamente con el rendimiento en ambas materias en las economías avanzadas.O objetivo deste estudo foi examinar, simultaneamente, as relações entre a qualidade do professor e o tempo de instrução e os resultados em matemática e ciências de grupos do último ano do ensino básico (8th grade) em 18 economias avançadas e em desenvolvimento. Para além disso, o estudo examinou as mudanças no desempenho em matemática e em ciências entre os dois grupos de economia ao longo do tempo, usando dados das avaliações do TIMSS 1995-2007. Embora a economia não conte para a variação nos resultados em matemática e ciências, os resultados das análises de regressão indicam relações significativas entre as condições das escolas e os resultados em ambos os grupos de países, ao longo dos anos. A experiência de ensino foi um forte indicador do desempenho em matemática em países em desenvolvimento, enquanto o tempo de instrução relacionou-se moderadamente com os resultados alcançados em ambas as disciplinas em economias avançadas

Two-dimensional heterogeneous photonic bandedge laser

We proposed and realized a two-dimensional (2D) photonic bandedge laser surrounded by the photonic bandgap. The heterogeneous photonic crystal structure consists of two triangular lattices of the same lattice constant with different air hole radii. The photonic crystal laser was realized by room-temperature optical pumping of air-bridge slabs of InGaAsP quantum wells emitting at 1.55 micrometer. The lasing mode was identified from its spectral positions and polarization directions. A low threshold incident pump power of 0.24mW was achieved. The measured characteristics of the photonic crystal lasers closely agree with the results of real space and Fourier space calculations based on the finite-difference time-domain method.Comment: 14 pages, 4 figure

In Utero Exposure to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Affects the Development of Reproductive System in Mouse

PURPOSE: Exposure of male reproductive organs to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) has been reported to cause developmental changes. In this study, we evaluated the effects of in utero TCDD exposure on male reproductive development. MATERIALS AND METHODS: Pregnant C57BL/6 mice were administered a single intraperitoneal injection of TCDD (1microgram/kg) on gestation day (GD) 15. The offspring were examined in the immature stage on postnatal day (PND) 30 and in the mature stage on PND 60. The testes were examined for histological changes, androgen receptor (AR), proliferating cell nuclear antigen (PCNA) and apoptosis following the measurement of morphological changes. RESULTS: Anogenital distance (AGD) and testis weights were reduced by TCDD exposure both on PND 30 and PND 60 while body weights and length of male offspring were not affected by TCDD. The regular sperm developmental stage was impaired with TCDD treatment on PND 30. However, no difference was found between the control group and TCDD groups on PND 60. Simultaneously, the expression of AR was also reduced on PND 30, while it was increased on PND 60 compared with the control group. The expression of PCNA was decreased whereas apoptosis was not affected by TCDD both on PND 30 and PND 60. CONCLUSION: These results suggest that in utero exposure to TCDD influences the development of testes by inhibiting the expression of AR and PCNA. Moreover, the adverse effects of TCDD on male offspring reduced over timeope

Successful mobilization using a combination of plerixafor and G-CSF in pediatric patients who failed previous chemomobilization with G-CSF alone and possible complications of the treatment

Peripheral blood stem cell (PBSC) mobilization, which uses plerixafor (AMD 3100), a newly developed specific inhibitor of the CXCR4 receptor, in combination with granulocyte-colony stimulating factor(G-CSF), has been shown to enhance the stem cell mobilization in adult patients, but pediatric data are scarce. We documented our experience with this drug in 6 Korean pediatric patients who had failed in chemomobilization, using G-CSF, alone. All patients were mobilized CD34+ cells (median, 11.08 × 106/kg: range, 6.34-28.97 × 106/kg) successfully within 2 to 3 cycles of apheresis, without complications. A total of 7 autologous transplantations were performed, including 1 tandem transplantation. However, 2 patients with brain tumors showed severe pulmonary complications, including spontaneous pneumomediastinum. This is the first study of PBSC mobilization with plerixafor in Asian pediatric patients. Furthermore our study suggests that mobilization with plerixafor may be effective in Korean pediatric patients, who have previously been heavily treated and have failed PBSC mobilization with classical chemomobilization, using G-CSF. However, further studies are needed to examine the possible complications of autologous transplantation, using a mobilized plerixafor product in children

Prospective evaluation of clinical symptoms of chemotherapy-induced oral mucositis in adult patients with acute leukemia: A preliminary study

Objective The objective of this study was to prospectively evaluate the clinical features of chemotherapy-induced oral mucositis (CIOM) in adult patients with acute leukemia and the aggravating factors for such symptoms. Subjects Thirty-seven prospective patients aged >= 19 years with acute leukemia undergoing chemotherapy were enrolled. Oral and clinical investigations were performed at baseline and on Day 14 after starting chemotherapy. The presence and severity of cancer-induced oral mucositis were demonstrated using the World Health Organization (WHO) scoring system. Results On Day 14, we found that oral mucositis had developed in eight patients (21.6%). Hematopoietic stem cell transplantation (HSCT) in patients was a predictor of increased WHO scores (beta = 1.937, p < .001). Regarding oral sites, ventral tongue (beta = 1.670), soft palate (beta = 1.242), and buccal mucosa (beta = 0.593) were predictors for increased scores. In addition, the increase in WHO scores was positively correlated with the number of oral lesions (r = .521), the difficulty in eating (r = .250), and the overall oral health (r = .534; all p < .05). Conclusion The main factors affecting the severity of CIOM symptoms were the treatment with HSCT and the location of oral lesions. The incidence of CIOM and WHO scores were not significantly different between the subgroups of disease. Our findings will help clinicians investigate the oral findings after chemotherapy in adult patients with acute leukemia.Y

A Study on Apparel Design for Chiropractic Training

In severe cases of spinal misalignment due to wrong back posture during adolescence or focusing on work, modern people can have back pain. Such a symptom is commonly referred to as scoliosis and it already became one of the lifestyle diseases. Hence, the purpose of the present study was to develop a functional musculoskeletal correction wear that can help with maintaining a correct posture by relaxing tonic muscles and maximizing the tension of the relaxed muscle using the principle of sports taping. Market research for design development was conducted at department stores and specialty road shops separately. Department stores were visited on weekdays when the store is not crowded, and specialty road shops were visited at around three o’clock on weekdays after checking their opening, lunch, and closing times. Since the apparel should not interfere with exercise movements while maintaining the body shape, the survey was carried out mostly on yoga and lifestyle training apparel focusing on elasticity and percentage of blending fiber. A camera and audio recorder were prepared and took pictures of clothing tags that show the ratio of polyester and spandex while trying on and checking products at the stores. Data were collected by asking the staff at road specialty shops who has more professional knowledge about the advantages and functions of the existing products and recording their answers. Point color schemes in black color family in which body shapes can look beautiful were mostly checked. Due to the design characteristics that have to maintain the spine, the designs of all-in-one products that can maintain the upper and lower torsos were checked at underwear stores. The existing products were evaluated for their designs to be adopted including the material, integrated into the new design, and then modified and supplemented, and the following chiropractic apparel design was drawn (Table 1). An all-in-one design that wraps around the hips and upper thighs for easy counterbalancing between the upper and lower body was chosen. A design with an accent line that makes body shape looks beautiful and Used compression wear material that is comfortable for activities and presses tight against the skin. Activates the muscle activities of latissimus dorsi muscle using taping method, and provides tension to maintain correct posture of round back and shoulders. In conclusion, prevention, exercise, and stretching are important for scoliosis and sound posture for the loin should be constantly maintained. To that end, not only the proper use of chairs but also apparel that is worn all the time can be helpful