Learner-friendly textbooks: Chemistry texts based on a constructivist view of learning

In this study, the use of inquiry methods, learning cycles, a conceptual change model and analogy in creating alternative science texts was discussed. An alternative text on the topic of acids and bases was created by integrating the methods and models discussed in this paper. The alternative text and a sample of a traditional text taken from a textbook, which is still used in Turkish high schools, were given to two groups, totaling 42 pre-service teachers—the alternative text was given to an experimental group and the traditional text to a control group—in an experimental setting and their understandings of acids and bases were compared. In addition, in the second step of the study, the pre-service teachers read both texts and indicated their preferences in terms of interest, understandability and helpfullness.     

Kidney function change after transcatheter aortic valve replacement in patients with diabetes and/or hypertension

Aortic stenosis(AS)is a progressive heart valve disease occurring predominantly in older patients.According to a survey in a western country,the prevalence of AS is nearly 6.4%in patients over 75 years old(Carabello and Paulus,2009).Transcatheter aortic valve replacement(TAVR)is an alternative method for AS patients.Previous studies have described how up to 66%of TAVR patients have concomitant baseline kidney dysfunction(Ferro et al.,2015;Gargiulo et al.,2015).The majority of patients can benefit from the TAVR procedure with the recovery of kidney function.     

试论民间剪纸的版权主体及版权享有

在各种传媒上发表和在展览馆展览的具有艺术性质的民间剪纸,其版权主体为域群和剪纸作者,域群和剪纸作者共同享有精神权——署名权和财产权——域群享有版权的20％,剪纸者享有80％。     

A Bandwidth expanding scheme for communication channels with noiseless feedback in the presence of unknown jamming noise

This paper treats the problem of transmitting a Gaussian discrete-time Markov process over a time-discrete additive white Gaussian channel with noiseless feedback which is subjected to statistically unknown jamming noise (satisfying a given power constraint). The channel is used more than once during the interval between the production of successive source letters, and the jamming noise is either allowed to be correlated with the encoder output, or forced to be totally independent of it. The complete solution obtained in the paper under a minimax criterion indicates that the optimum encoder-decoder structures are linear,and the least favorable jamming noise is a Gaussian process.     

Effects of axial conduction in laminar tube flow with convective boundaries

Heat transfer in laminar tube flow with convective boundary conditions and axial heat conduction in the fluid is solved exactly. The effects of the external Biot numbers and the axial conduction in fluid on the temperature distribution and the local Nusselt number are determined for both the upstream and the downstream regions. In order to illustrate the effects of velocity profile, the results for the slug flow and the parabolic velocity profiles are plotted simultaneously. The heat transfer characteristics of the flow are found to be rather sensitive to the Péclét number, the external Biot numbers and the velocity profile in the thermal entrance region.     

Serum Ischemia-Modified Albumin in Preterm Babies with Respiratory Distress Syndrome

Infants with respiratory distress syndrome (RDS) may suffer from severe hypoxia, asphyxia. In this study, we aimed to evaluate serum ischemia-modified albumin (IMA) level as a diagnostic marker for hypoxia in preterm infants with RDS. Thirty-seven premature newborns with RDS were allocated as the study group and 42 healthy preterm neonates were selected as the control group. IMA was measured as absorbance unit (ABSU) in human serum with colorimetric assay method which is based on reduction in albumin cobalt binding. IMA levels were significantly higher in neonates with RDS as compared to the control group (P < 0.001). Cut-off value of IMA (ABSU) was 0.72, the sensitivity level was 91.9 %, the specificity was 78.6 %, positive predictive value was 79.1 % and negative predictive value was 91.7 % at RDS. Area under curve values was 0.93 (P < 0.001; 95 % CI, 0.88–0.98) in the receiver operating characteristic curve. We concluded that elevated blood IMA levels might be accepted as a useful marker for hypoxia in newborn with RDS.     

天人合一－华兹华斯诗《失去的恋情》赏析

华兹华斯是19世纪英国诗坛的一颗巨星，他运用简朴的语言再现了普通生活中的平凡事件，平凡中饱含着诗人炽热的情感，蕴含着诗人与大自然，诗中人与大自然的契合，达到了天人合一的绝妙境界。     

Zp上的矩阵A的左(右)逆

基于Zp 上的加法和乘法运算 ,定义了Zp 上的矩阵A及有关概念 ,讨论了Zp 上的方阵可逆及s×n矩阵存在左 (右 )逆矩阵的充分必要条件。