Collaborative Learning Problems and Identity Salience: A Mixed Methods Study

Peer collaborative learning that emphasizes collaboration among peers has attracted a great deal of interest since the last two decades of the 20th century (Dornyei, 1997; Martin, 2007). Other than proved academic advantages, many collaborative groups were ineffective and failed to generate any collaborative actions (Hardy, Lawrence, & Grant, 2005; Johnson & Johnson, 1996). Identities are motivators of human actions (Stryker, 1968), which impact students’ behavior tendencies to be contributing or preventing to the occurrence of the collaborative learning problems. The purpose of this study was to explore students’ behavioral tendencies in dealing with collaborative learning problems in relation to their identity salience. A total of 17 graduate students were selected from 143 survey participants to participate in in-depth interviews. This study applied a sequential, mixed methods design with the participant selection model (Creswell & Plano-Clark, 2007). Results of the study disclosed the relationship between students’ identity salience and their behavioral tendencies in dealing with collaborative learning problems: group tension, the free-rider effect, and role taking

Levels of attachment disorganization: its precursors and pathways toward maladaptation

This dissertation research examined both the etiology of attachment disorganization and the pathways from attachment disorganization levels at 12 months to maladaptation at 36 months. Regarding the etiology of attachment disorganization, hypotheses were made that parental harsh and negative behaviors would be a significant predictor of children's attachment disorganization levels at 12 months in the Strange Situation Procedure within a diverse community sample. Additionally, moderational mechanisms were tested in the association between harsh and negative parenting and children's disorganization levels in attachment. Regarding the pathways from attachment disorganization to maladaptation at 36 months, the direct link between the two constructs were tested first, and then multiple moderational pathways were examined in the association between early attachment disorganization levels and externalizing behaviors at 36 months. This research found that harsh negative parenting was a significant predictor of children's levels of disorganization in attachment. In addition, this association was contingent on the levels of parental belief in discipline and control in that harsher and more negative parenting was significantly related to children's levels of attachment disorganization at 12 months only when it was paired with strong parental belief in discipline and control,. In contrast, when children had difficult temperament at 6 months, it was only when parents held very weak beliefs in discipline and control that children were at the higher risk for attachment disorganization. When examining the pathways toward maladaptation, this research found that attachment disorganization levels was a significant predictor of children's externalizing behaviors at 36 months. This link was also contingent on the number of children at home in that higher levels of disorganization were associated with higher externalizing behaviors only when there were one or more siblings living at home. In addition, child difficult temperament at 12 months served as a unique predictor of children's externalizing behaviors at 36 months above and beyond the prediction of attachment disorganization levels which suggests multiple avenues in the development of early externalizing behaviors. In sum, this research highlights the importance of examining the specific conditions under which risk or maladaptation may arise

Integrating Cell Phones into a Chinese High School EFL Classroom: Students’ Attitudes, Technological Readiness, and Perceived Learning

Although explorations on cell phone-based learning (C-learning) in the field of teach­ing English as a foreign language (EFL) has been gaining increasing attention in the last 10 years, the explorations are constrained mainly to distance language teaching. Researchers have pointed out that mobile devices are most effective when combined with group activities, tradi­tional educational activities, and other information and communication technologies (Librero, Ramos, Ranga, Trinona, & Lambert, 2007; Stead, 2005). The purpose of this study was to in­vestigate the integration of a C-learning activity into a traditional EFL classroom by looking at students’ attitudes, technological readiness, perceived learning, and perceived appropriateness of the activity design. A total of 96 high school students from Xiamen, China participated in the study. Students’ survey responses, reflection papers, and final projects were collected and ana­lyzed. Findings of the study indicated that students enjoyed the activity. They found the activity interesting, inspiring, and effective for their English learning. Students had no technological anxieties related to the cell phone use. This study can contribute to the discussion on integrating cell phones for EFL teaching by providing a sample activity as well as students’ possible percep­tions and attitudes toward the activity

Gonadal tumor risk in pediatric and adolescent phenotypic females with disorders of sex development and Y chromosomal constitution with different genetic etiologies

ObjectivesThis retrospective study sought to investigate the risk and proportion of gonadal neoplasms in phenotypic female pediatric patients with DSD and the presence of the Y chromosome and different genetic backgrounds in a single Chinese center.Materials and MethodsFrom January 2012 to December 2020, pediatric and adolescent patients with DSD and the presence of the Y chromosome who had unambiguous female genitalia and underwent bilateral gonadectomy or gonadal biopsy were included in this study. Patients’ demographics, karyotype, laboratory test results, gross pathology, and histology of gonadal tissue were all collected. The patients were divided into three groups based on their different genetic backgrounds, and the percentage of gonadal tumors was calculated to assess the risk of gonadal tumor and malignancy by etiology.ResultsA total of 22 patients with DSD and an unambiguous female phenotype with a Y chromosome were recruited. The mean age was 10.91 ± 4.99 years (9 months to 19 years). Gonadal neoplasia was confirmed in six (27.3%) cases by pathological examination of surgical gonadal tissue samples. Among 44 gonadal samples from these 22 patients, the following were identified: five gonadoblastomas, three dysgerminomas, and two Leydig cell tumors. The youngest patient with a tumor was a 2-year-old girl with 46,XY complete gonadal dysgenesis (46,XY CGD or Swyer syndrome) and bilateral gonadoblastoma. Patients with 46,XY complete gonadal dysgenesis (4/6; 66.7%) had the highest tumor occurrence rate. Among 10 patients with Turner syndrome with the presence of the Y chromosome, only one patient was diagnosed with a gonadal tumor. Leydig cell tumor was diagnosed in only one of six patients with 46,XY androgen synthesis/action disorders.ConclusionPediatric patients with 46,XY complete gonadal dysgenesis had a significantly increased risk of developing gonadal tumors and underwent prophylactic gonadectomy as soon as the diagnosis was confirmed, whereas those with Turner syndrome with Y chromosome and 46,XY androgen synthesis/action disorders had a relatively low risk. In view of the limited number of patients, a large multicenter study with close follow-ups is needed to support these conclusions

A Three-Step Model for Designing Initial Second Life-Based Foreign Language Learning Activities

Abstract The use of three-dimensional virtual worlds such as Second Life (SL) to support foreign language learning and teaching has been receiving increasing attention over the last decade. A review of the literature revealed a lack of activity design models for SL-based foreign language learning. This paper proposes a model that may be used by foreign language educators to design initial SL-based learning activities for their students. The suggested model integrates three language-learning features to contribute to effective language learning, to satisfy students' preference for working in groups, and to reduce SL's chances of crashing. The model also provides a mechanism for moderating SL's steep learning curve

Catalytic liquefaction of sewage sludge to small molecular weight chemicals

The catalytic hydrotreatment of sewage sludge, the wet solid byproducts from wastewater treatment plants, using supported Ir, Pt, Pd, Ru catalysts had been investigated with different solvent conditions. Reactions were carried out in a batch set-up at elevated temperatures (400 °C) using a hydrogen donor (formic acid (FA) in isopropanol (IPA) or hydrogen gas), with sewage sludge obtained from different sampling places. Sewage sludge conversions of up to 83.72% were achieved using Pt/C, whereas the performance for the others catalysts is different and solvent had a strong effect on the conversion rate and product constitution. The sewage sludge oils were characterised using a range of analytical techniques (GC, GC–MS, GCxGC, GPC) and were shown to consist of monomers, mainly alkanes and higher oligomers

TiAVox: Time-aware Attenuation Voxels for Sparse-view 4D DSA Reconstruction

Four-dimensional Digital Subtraction Angiography (4D DSA) plays a critical role in the diagnosis of many medical diseases, such as Arteriovenous Malformations (AVM) and Arteriovenous Fistulas (AVF). Despite its significant application value, the reconstruction of 4D DSA demands numerous views to effectively model the intricate vessels and radiocontrast flow, thereby implying a significant radiation dose. To address this high radiation issue, we propose a Time-aware Attenuation Voxel (TiAVox) approach for sparse-view 4D DSA reconstruction, which paves the way for high-quality 4D imaging. Additionally, 2D and 3D DSA imaging results can be generated from the reconstructed 4D DSA images. TiAVox introduces 4D attenuation voxel grids, which reflect attenuation properties from both spatial and temporal dimensions. It is optimized by minimizing discrepancies between the rendered images and sparse 2D DSA images. Without any neural network involved, TiAVox enjoys specific physical interpretability. The parameters of each learnable voxel represent the attenuation coefficients. We validated the TiAVox approach on both clinical and simulated datasets, achieving a 31.23 Peak Signal-to-Noise Ratio (PSNR) for novel view synthesis using only 30 views on the clinically sourced dataset, whereas traditional Feldkamp-Davis-Kress methods required 133 views. Similarly, with merely 10 views from the synthetic dataset, TiAVox yielded a PSNR of 34.32 for novel view synthesis and 41.40 for 3D reconstruction. We also executed ablation studies to corroborate the essential components of TiAVox. The code will be publically available.Comment: 10 pages, 8 figure

Data-Driven Distributed Optical Vibration Sensors: A Review

Distributed optical vibration sensors (DOVS) have attracted much attention recently since it can be used to monitor mechanical vibrations or acoustic waves with long reach and high sensitivity. Phase-sensitive optical time domain reflectometry (Φ-OTDR) is one of the most commonly used DOVS schemes. For Φ-OTDR, the whole length of fiber under test (FUT) works as the sensing instrument and continuously generates sensing data during measurement. Researchers have made great efforts to try to extract external intrusions from the redundant data. High signal-to-noise ratio (SNR) is necessary in order to accurately locate and identify external intrusions in Φ-OTDR systems. Improvement in SNR is normally limited by the properties of light source, photodetector and FUT. But this limitation can also be overcome by post-processing of the received optical signals. In this context, detailed methodologies of SNR enhancement post-processing algorithms in Φ-OTDR systems have been described in this paper. Furthermore, after successfully locating the external vibrations, it is also important to identify the types of source of the vibrations. Pattern classification is a powerful tool in recognizing the intrusion types from the vibration signals in practical applications. Recent reports of Φ-OTDR systems employed with pattern classification algorithms are subsequently reviewed and discussed. This thorough review will provide a design pathway for improving the performance of Φ-OTDR while maintaining the cost of the system as no additional hardware is required

Synthesis of thiolated chitosan and preparation nanoparticles with sodium alginate for ocular drug delivery

Purpose: The goal of the present study was to synthesize mucoadhesive polymer -thiolated chitosan (TCS) from chitosan (CS), then prepared CS/TCS-sodium alginate nanoparticles (CS/TCS-SA NPs), determined which was more potential for ocular drug delivery. Methods: A new method for preparing TCS was developed, and the characteristics were determined using Fourier transform infrared spectroscopy and the degree of thiol immobilized was measured by Ellman's reagent. Human corneal epithelium (HCE) cells were incubated with different concentrations of TCS for 48 h to determine the cell viabilities. CS/ TCS-SA NPs were prepared and optimized by a modified ionic gelation method. The particle sizes, zeta potentials, Scanning electron microscopy images, mucoadhesion, in vitro cell uptake and in vivo studies of the two types of NP were compared. Results: The new method enabled a high degree of thiol substitution of TCS, up to 1,411.01±4.02 μmol/g. In vitro cytocompatibility results suggest that TCS is nontoxic. Compared to CS-SA NPs, TCS-SA NPs were more stable, with higher mucoadhesive properties and could deliver greater amounts of drugs into HCE cells in vitro and cornea in vivo. Conclusions: TCS-SA NPs have better delivery capability, suggesting they have good potential for ocular drug delivery applications

Association between maternal sensitivity and externalizing behavior from preschool to preadolescence

Using data from the longitudinal NICHD Study of Early Child Care and Youth Development (N=1364), this study examined the association between mothers’ sensitivity and children’s externalizing behavior from preschool to preadolescence. Externalizing behavior declined on average across this period with a slowing of this decline around middle childhood. Maternal sensitivity remained relatively stable on average, and there was significant variation across mothers. A decrease in maternal sensitivity from ages 3 to 11 was related to an increase in externalizing behavior from ages 4 to 12. A model-based test of the direction of the effect suggested that the association between changes in maternal sensitivity and externalizing behavior from ages 4 to 11 was driven by child effects on mothers and not vice-versa. Between late preschool age and preadolescence, the behavior problems of children appear to strongly influence the sensitive support of mothers. Practical implications were discussed in light of these findings