Trust in Electronic Markets, A Review and Synthesis of Theories

Electronic markets have grown substantially, and they are considered as a significant form of retail. Despite this growth, the lack of physical transactions between different parties as well as concerns about the privacy of users and the security of transactions has led to a decline in users’ trust in these platforms. This deficiency has motivated many researchers to study the concept of trust in the e-commerce environment. In this paper, we have created a comprehensive and up-to-date framework that synthesises the findings of the previous studies. To achieve this aim, we use a systematic literature review method. We searched 17 top-ranked information systems journals and conferences and reviewed the resultant pool of 127 papers. Beyond investigating the antecedents and consequences of trust in e-commerce, we reviewed the theoretical basis used in the literature. The study concludes with implications of the literature for practice and a critical agenda for future research

Parametric Level Set Methods for Inverse Problems

In this paper, a parametric level set method for reconstruction of obstacles in general inverse problems is considered. General evolution equations for the reconstruction of unknown obstacles are derived in terms of the underlying level set parameters. We show that using the appropriate form of parameterizing the level set function results a significantly lower dimensional problem, which bypasses many difficulties with traditional level set methods, such as regularization, re-initialization and use of signed distance function. Moreover, we show that from a computational point of view, low order representation of the problem paves the path for easier use of Newton and quasi-Newton methods. Specifically for the purposes of this paper, we parameterize the level set function in terms of adaptive compactly supported radial basis functions, which used in the proposed manner provides flexibility in presenting a larger class of shapes with fewer terms. Also they provide a "narrow-banding" advantage which can further reduce the number of active unknowns at each step of the evolution. The performance of the proposed approach is examined in three examples of inverse problems, i.e., electrical resistance tomography, X-ray computed tomography and diffuse optical tomography

A Predictive Model for Assessment of Successful Outcome in Posterior Spinal Fusion Surgery

Background: Low back pain is a common problem in many people. Neurosurgeons recommend posterior spinal fusion (PSF) surgery as one of the therapeutic strategies to the patients with low back pain. Due to the high risk of this type of surgery and the critical importance of making the right decision, accurate prediction of the surgical outcome is one of the main concerns for the neurosurgeons.Methods: In this study, 12 types of multi-layer perceptron (MLP) networks and 66 radial basis function (RBF) networks as the types of artificial neural network methods and a logistic regression (LR) model created and compared to predict the satisfaction with PSF surgery as one of the most well-known spinal surgeries.Results: The most important clinical and radiologic features as twenty-seven factors for 480 patients (150 males, 330 females; mean age 52.32 ± 8.39 years) were considered as the model inputs that included: age, sex, type of disorder, duration of symptoms, job, walking distance without pain (WDP), walking distance without sensory (WDS) disorders, visual analog scale (VAS) scores, Japanese Orthopaedic Association (JOA) score, diabetes, smoking, knee pain (KP), pelvic pain (PP), osteoporosis, spinal deformity and etc. The indexes such as receiver operating characteristic–area under curve (ROC-AUC), positive predictive value, negative predictive value and accuracy calculated to determine the best model. Postsurgical satisfaction was 77.5% at 6 months follow-up. The patients divided into the training, testing, and validation data sets.Conclusion: The findings showed that the MLP model performed better in comparison with RBF and LR models for prediction of PSF surgery.Keywords: Posterior spinal fusion surgery (PSF); Prediction, Surgical satisfaction; Multi-layer perceptron (MLP); Logistic regression (LR) (PDF) A Predictive Model for Assessment of Successful Outcome in Posterior Spinal Fusion Surgery. Available from: https://www.researchgate.net/publication/325679954_A_Predictive_Model_for_Assessment_of_Successful_Outcome_in_Posterior_Spinal_Fusion_Surgery [accessed Jul 11 2019].Peer reviewe

Pre-Differentiated Embryonic Stem Cell versus Olfactory Ensheathing Cell for Spinal Cord Regeneration after Compressive Injury in Rat

Background: Transplantation approaches are interventions currently available to apply to the devastating problem of spinal cord injury (SCI). Olfactory ensheathing cell (OEC) and embryonic stem cell (ESC) are considered to be promising therapeutic strategies. In this study, we compared the potential use of OECs and neurally pre-differentiated ESCs in contusion spinal cord.Methods: OECs were harvested from olfactory bulb of rats and labeled with Hoescht 33342. ESCs were generated by using feeder free GFP positive CGR8 mouse ESCs and neurally pre-differentiation was induced by retinoic acid (RA) and characterized by different antibodies. SCI was induced by fogarty catheter at T8-T9 level in adult rats. Transplantations were performed 9 days after the injury. Rats were randomly divided into 3 main groups (neurally pre-differentiated ESC, OEC and media as control group). The recovery of gross motor function was evaluated using Basso-Beattie-Bresnahan (BBB) locomotor rating scale on the ninth day post injury and once per week thereafter for 4 weeks after cell transplantation. At 28 days after transplantation, histological assessment including transplanted cell detection in tissue, tissue sparing and myelinated axons was performed.Results: Following transplantation, a significant recovery of hindlimb function according to BBB scale was observed in rats in the transplanted groups compared to control and sham groups (p<0.05). There was no significant difference between transplanted groups four weeks after transplantation. OEC and ESC were found in the tissue after transplantation. In OEC group, many of OECs were detected around and within the cystic cavity that number of these cells was significantly higher in comparison with number of cells in ESC group (p< 0.001).In the site of injury, several cavities were produced that disrupted portions of the gray and white matters. The extent of tissue damage was more severe in the sham and control groups than the other groups. Significantly more spinal tissue was spared in OEC and ESC groups (P < 0.001). No significant difference in percentage of spared tissue was found between sham and control groups or transplanted groups. The percentage of myelinated area was greater in OEC group than in three other groups (p< 0.05) (Figure 5, A). Although the percentage of myelinated area was more in ESC group in comparison with non-treated groups, but this difference was not significant.Conclusion: It seems that using of combination of a myelinating cells like OEC or schwann cell and source of cells to replace dead cells like Mesenchymal or embryonic stem cells, better results can be obtained due to probable synergic effects of these cells

Is Urinary Interleukin-8 a Marker of Vesicoureteral Reflux in Children?

Introduction: Developing non-invasive but accurate methods to diagnose vesicoureteral reflux (VUR) is in progress. Cytokines, such as interleukin-8 (IL-8), are important mediators in inflammatory responses and are demonstrated to change during UTI and pyelonephritis, as well. Therefore, we attempted to evaluate the differences of IL-8 in children with UTI compared to children with and without VUR to assess if it can be hypothesized to be an appropriate diagnostic marker in children with VUR.Materials and Methods: We evaluated urine levels of IL-8 in 41 children aged 1 to 60 months who recovered from UTI for a minimum duration of 2-3 weeks. They were divided into 2groups: A and B (with and without VUR, respectively). Additionally, a group of normal children was considered as the control group (group C). Urine IL-8 levels were measured for the three groups and corrected for urine creatinine (Cr) (IL-8/Cr). Afterwards, they were compared using One-Way ANOVA test.Results: The mean IL-8/Cr level was 81.7 ± 90.1 in group A, 289.8±640.2 in group B, and 9.6 ± 12.2 in group C with no significant difference (p=0.056).Conclusions: Our finding suggests there is no significant difference in urine IL-8/Cr levels between patients with and without VUR and therefore, we cannot propose IL-8 as a diagnostic marker for VUR. Keywords: Interleukin-8; Pediatrics; Pyelonephritis; Urinary Tract Infections; Vesico-Ureteral Reflux

Association between neutrophil geletinase-associated lipocalin and iron deficiency anemia in children on chronic dialysis

Background: Iron deficiency anemia (IDA) in children with chronic kidney disease (CKD) is common and associated with higher risk of death. Neutrophil geletinase-associated lipocalin (NGAL) is a small 25 kDa glycoprotein, a member of lipocalin superfamily that released at the response of cellular stress from different cells. In addition, NGAL was studied as an iron regulatory glycoprotein and regulator of iron related gene. The aim of the current study was to determine any association between serum NGAL and body iron status markers in children on chronic dialysis. Materials and Methods: This correlation study was carried out between May 2012 and May 2013 and evaluated all dialysis patients less than 19 years in pediatric dialysis centers in Isfahan that didn’t have exclusion criteria. They were 40 children, including 23 persons on hemodialysis (HD) and 17 persons dialyzed by peritoneal dialysis (PD). Furthermore, we selected 40 children as healthy controls. We examined the relationship between plasma NGAL levels and indices of anemia such as ferritin, transferrin saturation (TSAT) and serum iron (SI) in dialysis children. Results: Serum NGAL level in children on chronic dialysis (group including both PD and HD patients) was significantly higher than healthy controls (P = 0.008). Furthermore, in this group Serum NGAL level had inverse correlation with TSAT (P = 0.04, r = −0.22), SI (P = 0.04, r = −0.2), white blood cells (P = 0.045, r = −0.26) and serum ferritin (P = 0.006, r = −0.3). In addition, HD patients had higher serum NGAL level than PD patients (P = 0.048). Conclusion: High serum NGAL level in low TSAT group demonstrated that NGAL probably has an important role in IDA in children on chronic dialysis; therefore, it can be a new marker for diagnosis of IDA in CKD