Practical stability in terms of two measures for fractional order dynamic systems in Caputo's sense with initial time difference

The initial time difference practical stability in terms of two measures has been investigated for nonlinear fractional differential equations in Caputo's sense and these properties have been unified with Lyapunov-like functions to establish a comparison result.     

A meta-analysis of the impact of mobile learning on mathematics achievement

Education and Information Technologies - The technological developments of the twenty-first century have enabled the emergence of alternative teaching-learning models and instructional tools. One...     

Stability studies of common biochemical analytes in serum separator tubes with or without gel barrier subjected to various storage conditions

Introduction

The collected and shipped blood samples are exposed to a various extra-analytical factors prior to analysis. The aim of the study was to determine the stability of analytes in serum gel tubes and plain tubes exposed to a range of storage temperatures and times after centrifugation.

Materials and methods:

Fifteen healthy volunteers were recruited and venous blood was collected into four tubes, two with and two without gel separator. Analyzing the baseline samples in 30 min, all were stored at 4ºC or 24ºC for 6, 12, 18, 24, 30, 36, 48 and 72 hours and 1 week. Sixteen biochemical anaytes were measured on each sample. Variations remained under the desirable bias considered as clinically insignificant.

Results:

On day three, most analytes remained stable including albumin, protein, creatinine, cholesterol, triglycerides, gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), alanine aminotransferase (ALT), creatine kinase (CK), lactate dehydrogenase (LD) regardless of tube types. Glucose concentration decreased markedly (P = 0.001) beginning from the first hours of storage in plain serum. The stability maximized for the analytes including glucose, total bilirubin, urea nitrogen (BUN), uric acid stored at 4 ºC in gel tubes. Aspartate aminotransferase (AST) activity increased significantly (P = 0.002) up to 48-h, however bias was not significant clinically. High density lipoprotein (HDL) concentration was stable in gel tubes at 24 ºC, in plain tubes at 4 ºC stored up to 36-h.

Conclusion:

Serum gel or non-gel tubes might be used interchangeably for 11 analytes chilled or at 24 ºC, whereas some restrictions must be applied for glucose, AST, BUN, HDL, and uric acid.     

The happy artist: an empirical application of the work-preference model

The artistic labor market is marked by several adversities, such as low wages, above-average unemployment, and constrained underemployment. Nevertheless, it attracts many young people. The number of students exceeds the available jobs by far. A potential explanation for this puzzle is that artistic work might result in exceptionally high job satisfaction, a conjecture that has been mentioned at various times in the literature. We conduct the first direct empirical investigation into artists’ job satisfaction. The analysis is based on panel data from the German Socio-Economic Panel Survey. Artists on average are found to be considerably more satisfied with their work than non-artists, a finding that corroborates the conjectures in the literature. Differences in income, working hours, and personality cannot account for the observed difference in job satisfaction. Partially, but not fully, the higher job satisfaction can be attributed to the higher self-employment rate among artists. Suggestive evidence is found that superior “procedural” characteristics of artistic work, such as increased variety and on-the-job learning, contribute to the difference in job satisfaction.     

Parallel access by butterfly networks for any degree permutation polynomial and ARP interleavers

Using more processors for parallel turbo decoding is an important issue to speed up the processing at the receiver of a communication system. Butterfly networks used to map the addresses of extrinsic values represent an elegant and simple solution in parallel turbo decoding. Recently, it has been shown that quadratic permutation polynomial (QPP) interleavers allow an easy way to compute the control bits for a butterfly network. In this paper we show that not only QPP interleavers, but any degree permutation polynomial (PP) interleavers and almost regular permutation (ARP) interleavers also allow the same easy way to compute the control bits required in butterfly networks. As a consequence, it is useful to apply the butterfly networks in parallel turbo decoding when using these performant algebraic interleavers.     

Profile and Motivations of Registered Whole-Body Donors in Turkey: Istanbul University Experience

Little is known regarding the profiles of whole body donors in Muslim majority countries where donation is scarce. Therefore, this study aims to profile registered donors in Turkey by means of a survey. The explored data could be used to improve ongoing campaign efforts and ethical practices such as commemoration services. Registered donors of the donation programs at the two faculties of medicine of Istanbul University were compared with the national population and a cluster analysis was performed to reveal any concealed sub-groups. Data from 188 respondents were analyzed. The majority of registered donors were married (42%), male (65.4%), aged over 50 years (76%), held a tertiary education degree (49.7%), and were irreligious (58.5%). Cluster analysis revealed two groups with significantly different educational levels, marital statuses, and religious choices. Regarding whether their bodies could be used for education or research, the majority (64.5%) of the respondents left the decision to the anatomy department. Similarly, 73.8% approved indefinite use of their organs, body parts and/or skeletons. The respondents were also willing to share their medical history (94.2%) and personal information (81.6%) if needed. Motivational themes for body donation including usefulness, impermanence, religion, awareness, and kinship were devised after a thematic analysis. Among the respondents, 56.5% were registered organ donors and 63.3% were frequent blood donors. The results of this study provide data that may help revising informed consent forms, developing and implementing thanksgiving ceremonies, and selecting additional targets for supporting body donation campaign activities such as organ and blood donation units.     

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.     

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.