Parental Influence on Students’ Mathematics Achievement: The Comparative Study of Turkey and Best Performer Countries in Timss 2011

AbstractThis paper assessed the impact of students’ background and parents’ attitude towards their children on mathematics achievement across four countries which were participated to Trends in International Mathematics and Science Study (TIMSS) 2011. Since Republic of Korea, Singapore and Chinese Taipei were ranked as the first three countries in terms of the achievement in mathematics scores, they were selected for the comparison with Turkey. Multilevel logistic regression model was used to estimate coefficients and to model differences in mathematics achievement within and between schools for each country. Gender, student-parent relationship, possessions of computer, room and internet were taken as student level variables, while school composition by student economical background, discipline and safety of school climate were taken as school level variables. According to results, owning a desk was the most effective factor on achievement of students for both Turkey and Republic of Korea, at the student level. Furthermore, at school level, the most effective factor on achievement was found the school composition by student economical background for all countries

Piecewise linear approximations for the static-dynamic uncertainty strategy in stochastic lot-sizing

In this paper, we develop mixed integer linear programming models to compute near-optimal policy parameters for the non-stationary stochastic lot sizing problem under Bookbinder and Tan's static-dynamic uncertainty strategy. Our models build on piecewise linear upper and lower bounds of the first order loss function. We discuss different formulations of the stochastic lot sizing problem, in which the quality of service is captured by means of backorder penalty costs, non-stockout probability, or fill rate constraints. These models can be easily adapted to operate in settings in which unmet demand is backordered or lost. The proposed approach has a number of advantages with respect to existing methods in the literature: it enables seamless modelling of different variants of the above problem, which have been previously tackled via ad-hoc solution methods; and it produces an accurate estimation of the expected total cost, expressed in terms of upper and lower bounds. Our computational study demonstrates the effectiveness and flexibility of our models.Comment: 38 pages, working draf

Shiga Toxin-Associated Hemolytic Uremic Syndrome and Unexpected Course

Hemolytic uremic syndrome is a disease that often requires the transfusion of blood products. A child (two and a half years old, boy) with Shiga toxin-associated hemolytic uremic syndrome who developed respiratory distress after transfusion is presented. The patient was diagnosed with Transfusion-Related Acute Lung Injury (TRALI) after eliminating other possibilities. Transfusions may be complicated by a low rate of potential fatal transfusion-related reactions like TRALI

The Supraorbital Keyhole Approach

Conclusions: This anatomical study showed that structures in the anterior and middle cranial fossa can be reached via the supraorbital keyhole craniotomy approach with minimal brain retraction and adequate exposure and with minimal craniotomy size

Lymph Node Involvement in Endometrial Cancer

Objectives: The aim of this study was to evaluate the outcome of pelvic and/or para-aortic lymph node dissection in patients with endometrial cancer with regard to lymph node positivity.Materials and Methods: Retrospective chart review of 125 women with pathologically proven endometrial carcinoma who underwent a systematic surgical staging including lymphadenectomy between January 2006 and January 2011 was performed. Patients’ characteristics, histological findings, lymph node localization and involvement were analyzed. Detailed description of the extirpated and affected lymph nodes divided by area in the 125 patients with endometrial cancer were done.Results: The medical records for 125 patients were eligible for analysis. The mean number of all lymph nodes removed in operation was 38.9±14.194 (range 9 to 81 nodes). The mean number of pelvic lymph nodes (PLN) removed was 32±11.747 (range 9 to 75 nodes) and the mean number of para-aortic lymph nodes (PALN) removed was 7±5.123 (range 0 to 20 nodes). In the 24 patients with nodal metastasis, the mean number of all lymph nodes removed was 37.88±17.501 (range 9 to 81 nodes). The mean number of PLNs removed was 30.71±14.79 (range 9 to 66 nodes) and the mean number of PALNs removed was 7.17±4.198 (range 0 to 16 nodes).Nodal metastasis was shown in 24 (19.2%) patients. Isolated pelvic lymph node metastasis was shown in nine (37%) patients; isolated para-aortic lymph node metastasis was shown in one (4%) patient; both pelvic and para-aortic lymph node metastasis was shown in 14 (59%) patients. The most affected lymph node area was left external iliac artery with a ratio of 14%.Conclusions: In the field of gynecologic cancer surgery, for the determination of adequate number of lymph nodes to be retrieved, lymph node mapping plays a crucial role, and this issue should be investigated in studies performed with larger number of cases in order to standardize procedure of lymphadenectomy

In vivo effect of pregnancy on angiogenesis potential of arteriovenous malformation tissue samples: an experimental study

CONCLUSIONS: Findings of this study suggest that angiogenic activity of AVM tissues may increase during late pregnancy, hence physicians should inform pregnant patients with AVM of the potential risk